Duke Nukem 3D
Its just plain manly fun, murdering aliens and paying strippers is just manly (i guess?)
Ton of fun to play and the replay value is high since... well when you complete a level it gives you a score and who doesn't want to be the best liberator of humanity?
Great cut cenes, short nonetheless, but fun. accompanying it is a classic story about hero saving the world and rescuing the princess(es)
...did i mention strippers?

During the game, some very below-the-waistline jokes crop up. That's probably it. Oh, and if you check the Giants part of this forum, there's a guide on how to remove the censorship from the game. This means that one of the main characters in the game is topless, the way she was originally, before the publisher forced the developer to cover her up.

ok, well I don't really think it's necessary for me to un-censor the game. Pixels won't turn me on.

Nor me, it's more a matter of experiencing the game as the developers originally intended.