Undermount because it is so much easier to clean - you can just sweep crap from the counters right into the sink and there isn't that edge that inevitably becomes a gunk trap.

Most people opt for single bowls because they are much more functional. You can place large pans and sheets without having to maneuver around the divider.

Double bowl sinks (IMO) are an anachronism from when people would fill up one bowl with suds to wash dishes and then rinse in the other. You can always get the functionality of a double bowl if necessary by placing a bowl in one side but you can never get the functionality of a single large bowl with a divider.

In my current remodel I opted for a relatively large 36" single bowl with a ledge configuration. The ledge is designed to hold a grid (for draining or washing or whatever); and a cutting board. This means that my sink is effectively a more functional extension of the counter for prep as anything I need to wash is directly over the sink - i.e. no worries about cross contamination from chicken or whatever and any mess can be swept directly into the sink.

I opted for a drain on the left side in the rear which means that more real estate on the sink bottom is available since my drain would not be blocked if I am soaking a large pan. Moreover, it also frees up more usable space UNDER the cabinet since my garbage disposal is not in the middle - therefore instead of two small bits of open space on either side of the disposal, I have a large space to the right of the disposal which means there is room for a pull out trash container.

Top mount double, no question.

Do you hand wash daily? You'll probably prefer some variation of the two basin sink. I'll never go back and love a large, single basin. But I rarely handwash more than a single thing at a time.

Undermount versus drop-in is limited by what kind of countertop you have and what your budget is. Our previous kitchen renovation was an undermount SS sink in quartz. After living with it for 7 years, I didn't see the cost/benefit of undermount and chose a DIY cast iron drop in sink in my recent kitchen remodel.

Top mount if you want to put heavy pans in and fill them with water. I've had both. Go with top mount!

I suggest an under mount cast iron. It‘s easier to keep tidy and maintain since there is no caulk that runs along the countertop. I think it’s overall a cleaner look. I have a double sink with a small basin side for garbage disposal/small cleanups and a larger side for things like soaking pots. It really depends on how much hand washing you may do. Good luck with your project!

Perhaps visuals will help:

i'd vote for good sized single basin undermount.

Unless you have a laminate countertop, I don't know why you'd choose a top mount. The freedom of just wiping your crumbs and crud straight into the sink vs picking it out of the edges of the top mount speaks for itself.

Your second question is more complicated because it has to do with how you use a sink - not someone else, but you. Not only that, but people feel pretty strongly about their preferences. You just need to figure out how you use your sink and what your preferences are. This is a list I made to help a neighbor who is about where you are in the planning process. You may find as you read that you will have some AHA moments and recognize that a particular point of view resonates with you. IOW, there isn't a "right" answer, just an answer that rings true for you.

Really big sinks: https://www.gardenweb.com/discussions/2465743/does-anyone-have-the-galley-sink-how-do-you-like-it#n=67

Stainless Steel vs other types: https://www.gardenweb.com/discussions/2705122/anyone-regret-getting-stainless-steel-sink

Two large singles to make a large double? https://www.gardenweb.com/discussions/3679375/can-i-install-two-large-single-bowl-sinks-side-by-side

Best stainless steel sinks? https://www.gardenweb.com/discussions/4623870/who-makes-the-best-stainless-steel-sinks

Black granite (Silgranit) sinks: https://www.gardenweb.com/discussions/2670664/pros-and-cons-of-purchasing-a-black-granite-composite-sink

Best SS farmhouse sinks: https://www.gardenweb.com/discussions/3564493/what-is-the-best-brand-of-farmhouse-stainless-steel-sinks

Sink reveal, flush or positive: https://www.gardenweb.com/discussions/2663293/undermount-sinks-flush-or-reveal

Farmhouse sink? https://www.gardenweb.com/discussions/2456297/please-explain-the-allure-of-a-farmhouse-sink

Ledge sinks: https://www.gardenweb.com/discussions/2948796/ledge-sinks-and-accessories-do-you-use-them

16 gauge sinks: https://www.gardenweb.com/discussions/2705532/are-all-16-gauge-sinks-the-same

Sink grids? https://www.gardenweb.com/discussions/2974413/what-is-the-need-for-sink-grates-in-stainless-sinks

White sinks: https://ths.gardenweb.com/discussions/2626605/honest-opinion-on-white-sinks

What size sink in a 36" base? https://www.gardenweb.com/discussions/2690378/largest-sink-in-a-36-inch-sink-base

Drain placement: https://www.gardenweb.com/discussions/2685339/single-bowl-sinks-drain-centered-offset-pros-cons

50/50 and 60/40 divides: https://www.gardenweb.com/discussions/2678894/sinks50-50-or-60-40

Low divide sinks: https://www.gardenweb.com/discussions/2669873/what-are-the-pros-and-cons-of-a-low-divide

Sink price depending on where you buy it: https://ths.gardenweb.com/discussions/3955470/expensive-sinksworth-it

Cast iron farmhouse: https://www.gardenweb.com/discussions/4447916/33-kohler-white-farmhouse-sink-reviews

Silgranit vs stainless vs cast iron: https://www.gardenweb.com/discussions/2664181/sinks-which-type-silgranit-stainless-steel-or-cast-iron

More ledge sinks: https://www.gardenweb.com/discussions/3817452/kitchen-sink-decision-stages-vs-prolific-vs-something-else

Cleaning white Silgranit: https://www.gardenweb.com/discussions/4107932/reviews-on-white-silgranit-sink

60/40 vs single: https://www.gardenweb.com/discussions/2667336/60-40-sink-or-single-bowl

Sink & stove on same counter run: https://ths.gardenweb.com/discussions/2452373/sinks-and-stove-on-same-counter-run

Sink brand recommendations: https://www.gardenweb.com/discussions/5082431/what-are-the-best-sink-brands

Unless a top mount is poorly installed, there's no picking crud out, suzanne (sorry ninigret.) I chose a drop in cast iron in butcher block and I'm just as pleased as I was with ss undermounted in quartz (with thousands of more dollars in the bank.) There are valid reasons for all choices.

I would prefer an undermount single sink.

Top mount sinks have their own advantages but are out of fashion ( they are cheaper and easier to install and have less risk of dislodging over time). If you pick one you might want to avoid the cheap looking, builder grade sinks with a thick edge. The main problems with this choice are based on aesthetics and fashion not functionality. But there are some nice looking top mount sink options:

-If you have a modern kitchen you could look at the Kohler Vault, which is a dual mount stainless steel sink with a very thin edge, so thin it's possible to wipe crumbs past it. And it looks nice.

-If you have a traditional kitchen you could look at a top mount cast iron sink. Kohler makes several nice ones ranging in price. Cast iron sinks are a nice old fashioned look and don't look cheap or generic as some of the top mount stainless steel sinks might.

-Kohler makes both options with a "low divide" or "smart divide" which would allow you to use both halves separately while still fitting large items in the sink. It offers the best of both worlds as opposed to regular double and single bowl sinks.

A double bowl or single bowl is a personal preference. Personally I like a single bowl because I can fit larger pans in it to wash or soak. I love my under mount sink. I just brush the crumbs from the counter right into the sink. Yes, you can have a under mount sink with a laminate top. I have one. The sink has to be installed at the time of fabrication. It is not something that can be done after the counter is already installed. It is more what I call a flush mount. There isn't a lip above or below the sink.

Large single bowl undermount and I like stainless.

under-mount oversize single.

I put in a double bowl undermount six years ago & like it well enough. I figured it would be easier to not have to clean around the outside mount. I have found that the tiny little edge of the inside bowl gets almost as cruddy as around the outside of a top mount. My DH wanted a double bowl & I didn't care, as I was used to it. It is fine, even though I don't always hand wash. I hate the single bowl sink at my Dad's, so I feel I made a good choice.

My point being it is a question is similar to a poster showing up out of nowhere and asking:

"What Color Should I Paint My Cabinets?"

If you care do some research, or at the very least a word search on the topic in this forum.

Under vs top and single vs double is such personal preference.

I chose top mount because I like the look of it and it prevents granite chipping around the sink (such a heavily used area). I also chose a double bowl with low divide because I do a lot of handwashing and appreciate having "clean" and "dirty" sides in a sink, but the lower divide will still allow for larger items to be placed inside the sink.

I would stay away from Kohler Vault sinks, though....I ordered SIX Kohler Vaults, and they all had damage....I finally gave up on Kohler.

I run a sink replacement business. 90% of my replacements are single bowl undermount sinks and about half of those are apron style. Once in a while a low divide.

I replaced an equally divided undermount in a two-year-old home this afternoon with a single bowl. "I feel like I can breathe" she said.

I rarely get a damaged sink from Kohler and I buy a lot of sinks.

Thank you, all! I left it open on purpose to see what the trend is right now based on responses, and people's preferences in case I need to consider that for the future if we sell our home. I will look into these options!

in case I need to consider that for the future if we sell our home

While a few people like a top mount, the majority of home shoppers (not frequenters of this forum where people are very obsessed with kitchens) will prefer an undermount for the reasons stated above. If I were looking at a home to buy, and saw one that had a top mount sink in the kitchen, it would make me want to deduct the cost of a new counter and undermounted sink from the purchase price. It would not make me turn away from the home if it were otherwise nice, but I would definitely think "do over" for the sink, and mention it in the negotiation. If the home had other issues I did not like, the top mount sink might be the added thing to the list that would put me over the edge to turn me away from the home.

I love a single giant bowl undermount sink. So deep I can wash a small dog or put a giant lasagna pan in and bury my elbows deep in suds. Oh not washing the dog and lasagna together although the dog might like that. I also like that a deep single bowl can hide party dishes while guests hang out. And a big single bowl can fit a plastic washing tub for other cleaning. I do love the undermount because peelings or crumbs wipe right into the bowl.

Visit a kitchen design store or a lowes, or HD and check out their displays. Pretend you are cleaning a huge turkey pan or a pile of dirty dishes. Which do you like? How do you see yourself working in your kitchen? That will help you decide.

Usually an undercount sink looks more modern.. top mount is used really often if the worktop is laminate so that will seal better the wood.

About single or double bowl is really a personal matter.. If you have enough space I would go for a large double.

If you just want to go with the current trend, definitely get a single bowl undermount.