The general advice is to select, for each appliance, the brand and model that is best. Then don't worry about whether all the appliances are the same brand.

No single company makes the best of everything.

Grab the July Consumer Reports "Great Kitchens".

These are all good quality brands - I would say they are in the Lexus category.

As others have posted, it is generally good to focus on individual appliances and what features they have and whether the brand is particularly good for that type of appliance.

Research what features you do or don't want and then take some time to research the various options in each category. A visit (or several visits) to appliance stores that stock a good assortment of the ones you are interested in is critical.

I recently remodeled and wound up with an assortment of appliance brands after determining what features I wanted and which were good quality and which were in my price range

I knew I wanted a Bosch side opening oven.

I wanted an induction cooktop and within my price range the Bosch induction had the features that were important to me - e.g. how the controls works. So I wound up with a Bosch benchmark. If money were no object I would have gotten the $10,000 Gaggenau which had no separate hobs so you could place your pan anywhere on the surface so I compromised as the Bosch has two burners which can connect for large or long pans.

I was replacing a 14 year old Bosch which I was happy with so I didn't find a reason to not go with another Bosch dishwasher. They are considered to be leaders in their category and price range.

I was installing a microwave drawer so Sharp was an easy decision as all microwave drawers are made by Sharp and no reason to pay extra for the brand name.

The refrigerator was the toughest decision. Subzero was not in my price range at the time. I wanted French door without ice or water in the door and I wanted that would take panels as I didn't want a hulking stainless steel appliance where it would visually dominate. I went with a Kitchenaid as it had the features I wanted and was well reviewed. The more upscale sister company to Kitchenaid is Jennair. I looked at a model that was identical to the KA and neither my friend, the salesperson or I could discern any difference except the Jennair was more expensive :-).