HoMM rocks big time. I played that game for ages with my little brother. The only problem was we never finished a damn game, but always started new ones.
My favorite game genre is probably RPG (Baldur's Gate, KotOR etc.) but I like the occasional shooter (Unreal Tournament) and RTS (Dune 2, Warcraft III) as well. Come to think of it, the only thing I dislike are simulation games. I even played Pokémon a lot