for me
1. soft serve ice cream, like carvel
2. traditional frozen custard
3. hard ice cream (dont care for it at all really, unless its on top of something at a restaurant)

and i only get chocolate, or vanilla with sundae/at restaurant, so the whole "10 billion flavor" thing has no appeal for me. coldstone and ben and jerry's definitely go for the weird combinations---peanut butter cherry pie anyone? and baskin robbins is starting to go that route as well it seems.