I have to say I'm a big fan of Ben & Jerry's. My favorite is B&J Cinnamon Buns or B&J Banana on the Rum...which is VERY hard to find--I thik you can only get it in their stores.
(Which is probably a good thing for me!)
Although I was quite fond of Mayfield's B'day Cake when it first came out, but I think I ate so much of it that I burned myself out on it.