I love both granite & marble which I currently have in my kitchen. I have granite on the kitchen island:
I have marble on the ledge above the sink:
Using marble in the kitchen is very popular now for counter tops & back splashes.
For an awesome blog post regarding kitchen countertop options in marble click here!
Marble can get etched & pitted with all the work that goes on in a kitchen. Some people like that worn look.
If you are at that point trying to decide between granite and/or marble, another great resource is the blog 'The Granite Gurus'. Check it out for great info about choices & what to use to clean your granite!