I loved gamebooks as a kid. Choose Your Own Adventure, Time Machine, Find Your Fate, Which Way, Endless Quest, and the like.
I also remember FIghting Fantasy like Demons of the Deep, Seas of Blood, & Rebel Planet (I agree with gamebooks.org's reviewer that Rebel Planet is one awesome gamebook) and Way of the Tiger stuff like Avenger, and others where you had to roll dice during battles, select your skillset, and such. It was like single player D&D.
Good stuff, gamebooks.