Thanks for all of the replies!
I really like the idea of slate-- what do you think resale value is with that option? Probably not nearly as good as hardwood. I've been in a few homes with slate floors and they are gorgeous. I don't mind the cold, ect as well as we just wear shoes in the house (another reason I don't like carpet! Dirty husband boots = muck all the places).
I would think it's like any other flooring. If people like it, they like it, if not, they don't. I find carpet to bring value down, for me. Because I have to replace it
on the flip side, that is easy to change, so if I love the rest of the house, tearing it out and putting stuff I like down is not a problem. Much more so than if someone has picked out of paisley pink tile and I have to take that out and replace. ALthough it seems the way a lot of contractors are putting tile down these days, it's not as bad as it would seem.
But I think a nice slate would help, but if someone likes all of the house, but not the slate, i'm sure they're going to take that into account when making an offer knowing they really want to change at least some of it.
I've quit worrying about that though. If I need to be that liquid in my home ownership that resale value is of major concern, i'm not making any improvements anyway like that because i'll never get my money out of it. If I plan to stay for the long haul, i'm going to enjoy it and not worry about what the next person wants.