What kind of music do I like? Just about anything that strikes me as being nice to listen to. Since I don't experiment as much as I should, this tends to be stuff that's typically classified as "classic rock", plus anything else that's grabbed my interest.
Some artists who have done stuff that I like: Journey, Styx, Kansas, Bad Company, Black Sabbath, Dio, Tom Petty (in moderation only 😛) Three Doors Down, Queensrÿche, Jethro Tull, Bush, Creed, Billy Squier, Blue Ãyster Cult, whoever was responsible for the Akumajou Dracula X: Nocturne In The Moonlight soundtrack
As for a group that I can listen to for quite a while without getting sick of it, I think Queensrÿche would be the one, particularly if it's Operation: Mindcrime.