I've checked out a few hacks; Mostly (ms)pac-man or dkong related. And I'll probably work my way through the hbmame.lst to see what are hacks and try them out for fun.
I thought the Donkey Kong 2 (dkongx) and Pauline editions where kind of cool, but haven't really seen much else. Granted, I haven't gone through them all.
So, just curious if anyone else would care to list any the hacks they like or consider worth checking out?