What I want from a video game is to be completely addicted to it, whether that's for five hours or fifty. There isn't much I won't play, but I particularly like RPGs, action-adventure, platformers, and strategy games. That being said, my real passion is for stories. Video games are an exciting medium for story telling, with new and unique techniques opening up all the time, such as the reflexive, player driven stories of RPGs - or even the humble silent protagonist of old. Great characters and a strong plot are all-important and, if the gameplay is up to scratch as well, I'll play anything if it delivers on those.
A few favourites: Final Fantasy, Kingdom Hearts, Mass Effect, Uncharted, Assassin's Creed, Rayman, Ratchet and Clank, Legend of Zelda, Metroid, Bioshock Infinite, Total War.