I have a stainless steel sink in my kitchen and I love it. My husband wants to replace it with a white porcelain sink, but I put my foot down. The house I grew up in had a white porcelain sink and it ALWAYS looked dirty, no matter what.
However, I wish we still had our old porcelain bathtub. We gutted both bathrooms about 5 years ago, moved walls and plumbing, replaced the one tub we had with an acrylic one, and added another acrylic tub where we used to have just a shower. I HATE the acrylic tubs. Hate, hate, hate them!
As far as countertops, we have tile. My kitchen is all white, the countertops are red tile with white and black trim tile. It's very cheerful. I like tile because it's very easy to do (we installed it ourselves) and I don't have a problem with the grout - I spray it once a month or so with a bleach gel, leave it sit for 3-4 minutes, brush it with an old toothbrush, and wipe clean. We didn't go with granite or anything fancy, because it wouldn't have fit the style of our house (a 70's ranch).