Monkey Island, Day of the Tentacle, Indiana Jones and the Last Crusade/Fate of Atlantis
The last two are more serious.
My brothers and I still crack jokes from Monkey Island and DOTT. So good. If you don't laugh out loud playing those games, you don't have a soul.
This is the kind of crap that I grew up on. We played these nonstop, watched Monty Python and have a mother with a filthy sense of humor. Made interacting with women really awkward for a very long time.
Also, if you like the adventure/rpg stuff, definitely look into Deus Ex 1 and 3 (which are currently on steam sale!!! $11.24 for all 3 DE games. You could easily get 50 hours of gameplay out of that). DE2 sucked. Chrono Trigger and FF3 have been keeping me busy on my mobile device. The Dig is fun, but it's very dry, similar to the Indiana Jones games.