I have one shelf and use that cabinet to store serving bowls, baskets, pitchers, crockpot, some Xmas serving pieces, and a hot chocolate maker (which I need to get rid of but somehow made it through the remodel).

I really dislike items stacked on top of each other. I have vertical slots for the hard-to-reach cabinets. Over my fridge I have platters and trays and over my oven I have baking pans.

Over my fridge is all my giant tupperware storage containers, a rarely used giant stainless steel mixing/serving bowl (for salads-to-go when we serve 40+ people for kid events), and the stove-top popcorn maker. They're light, bulky, and occasionally used (except the popcorn popper which is towards the front). I have tray storage above my ovens. If I didn't have it there, I'd put it over the fridge.

Couple of links for you Lisapoi (just in case you missed them)

http://ths.gardenweb.com/discussions/2689999/storage-for-sheet-pans-and-cutting-boards

http://ths.gardenweb.com/discussions/2601154/best-use-of-space-over-refrigerator

I intend to have a pullout over my fridge as the space is quite deep - over 36 inches- (inspired by Annkh's pullout) - check second link.

Rethink the wine. There will be enough heat produced by the fridge to spoil wine.

We have pullouts - wire baskets - that hold our ice bucket, crockpot, dutch oven, and juice boxes for the kids' lunches (need to keep them out of the kids' reach!).

I urge you to use a pullout over the fridge whether you put in slotted storage for trays or large pots and pans or whatever. A pullout will give you easier access from the front since the fridge and its handles will protrude at least a bit beyond the cabinets, and the pullout will also allow you to have access from the side if you store pots and pans or anything other than trays and cookie sheets.

The two links Gemcap posted above contain pics that will help you envision your own use.

Wasted space over mine. The fridge extends 2 feet past the cabinet and I cannot reach it without a ladder.

Near the front I have my crock pot, the milkshake maker and my mini food processor. Towards the back are some baking pans I don't use very often. I need to stand on a step-stool or chair to reach those, but the rest I can reach easily. My roll of parchment paper rests on top of the crock pot. My cookie sheets are at the bottom of my pantry cupboard underneath the bottom pullout in the otherwise wasted space.

Half my space has the slots, the other half is a waste as far as I am concerned. I have pans that are rarely used, cookie jar, and a few other odds and ends. Whatever I want is at the back, it seems. And I can't reach it easily. Definitely go with slots and/or pull outs.

Mine is like camphappy's but the spaces between the slats are a little bit wider. I have cookie sheets and racks, my cutting boards, casserole dishes, lots of stuff. Mine is over a 36" fridge. I was considering going slats on just one side but so glad I did them right across.

I store my 3 crockpots there. They are only used a few times a year.

I have the same arrangement as camp happy too, with vinyl coated wire dividers instead of wood. Holds cutting boards, a fold up wooden dish rack, paper bags, cookie sheets, cooling racks, and trays. Very useful space and I would definitely make sure to include it the next time I redid my kitchen. I don't have any problem reaching up to grab something that is up there. You just need to be able to grab the front of the item and they easily slide forward.

I have a 48" SubZero and the cabinet above requires a step stool to reach it. So I keep some larger season items (mostly Halloween stuff) and my 20 quart stock pots that I generally only two once or twice a year. I have 10' ceilings and all of those upper shelves are full of seasonal items. I have vertical storage for pans/cookie sheets above my double ovens.

All of my cookie decorating stuff is in there, spritz cookie maker, piping bags, weird cake pans...not the stuff I use often, but specialty stuff. and my popcorn maker, maybe the pressure cooker.
My divided storage is above my oven for cookie sheets, cutting boards, etc.

Thank you for all the suggestions. I wasn't sure I wanted slats at first as my box is 24" deep, but you all are making me seriously reconsider this. I was thinking of building in two layers of shelving for my large plates (stacked), with large size serving bowls on the shelf above, but I know I will probably hate having to lift plates to get to the ones I want to use. I think I just thought to do it this way because its how I had it in my old kitchen . . . And I'm too tired of planning/ thinking to do anything different. I'm also definitely rethinking putting the wine up there though. Thank you for the heads-up on that!

I like the vertical storage space. It looks like it is made to hold old lp's, but it looks ideal for the things you have in it. I just store some extra glasses in mine for company. You ladies would be so shocked at my cabinets, pretty bare. I got rid of large pots and pans, stuff I will never use because I don't cook anymore, except for breakfast once or twice a week. I am retired. LOL My fridge is almost empty also. I told my husband one time "we may starve to death but we will never die of thirst". Pepsi, 7 UP, lemonade, milk, etc..

Mine is split into vertical and horizontal shelving. Shelving holds crock pots and other pots I don't remember, extra paper towel rolls, etc

Right now I have wasted space above my refrigerator. I hate it. I have two small cabinets that match my other upper cabinets . . . and this means that I have two un-reachable cabinets and a bit of empty space in front of them. I keep a picnic basket on the refrigerator on front of the worthless cabinets.

When we build, I plan to have vertical slat similar to CampHappy's above. I expect to use this for cookie sheets, wire cooling racks, muffin tins and other flat items. If space allows, I'd like to have a shelf above for cake pans and things that aren't used frequently.

The one idea I DON'T like is crock pots and other appliances. These are heavy, and I'm short. I fear that reaching high above my head for heavy items is an accident waiting to happen. Yes, I have a rolling stool that's wonderful -- but, still, I don't welcome the idea of heavy things above my head.

Mine is similar to campy happy with vertical slots I am just tall enough to (67 inches/170cm) reach everything in the slots without a step stool It has worked nicely for me

The items are relatively light weight- the heaviest item is my electric griddle which I hardly ever use as I bake bacon and use my induction for pancakes

Above the fridge is a short, 48" top-hinged door with no pull. It's the perfect place to hide things where no one else will think to look.

Mine is just a 12" deep by 12" high unreachable cabinet that I store extra egg cartons that are used when our chickens produce enough eggs to sell. On top of the fridge in front of the cabinet is our ice cream maker.

I store the huge enamelware stock pot that DH uses to make beer, my mom's enamelware roasting pan and a ridiculous amount of canning jars above my fridge. I plan to do the same after our remodel. I don't like storing anything too heavy so high up.

And as Sophie Wheeler pointed out, definitely do not store wine up there! Heat and wine is not a good combination. Find a cool, dark place to store your wine instead.

Mine is 24" deep, and tall enough that I have 3 levels -- the bottom has nearly all of my baking trays and shallow casserole/pans stored vertically, plus a salvaged plastic drawer with storage jars, straws, a few other rarely used but wanted once or twice a year pieces (like my large colander). The next shelf has my largest cookie sheets, cake pans, carving set and extra cutting board stored flat. The 3rd shelf is positioned just 3 inches above that and has things like extra sports bottles, left over rolls of shelf liner, canning jars and lids organized in more salvaged plastic drawers.

I intend to replace the plastic drawers with pullout baskets -- have them but haven't installed yet. But the plastic drawers are working pretty nicely actually because they don't have really heavy things and I can lift them down & back up into place easily.

I prefer vertical dividers. Have these over my fridge and I can still reach most of the time without using my small step stool (I'm 5'2"). After I took this photo I just noticed that there are holes that allow me to adjust the width of the spaces between dividers. Duh! Only took me 9 months to notice that!

Over my double ovens I have a horizontal shelf. Even though the bottom shelf is lower than that over my fridge, I find it more difficult to access and most always use the stool.