Very few FPS games have a distinctive sense of humor. Duke 3D set the (low?) bar for cheesy one-liners and gross-out, whereas ROTT is all about a goofy sense of fun along with the gibs. The first FPS I can remember with dual weapons, and some absolutely insane special items (god mode and dog mode especially). The attitude even seeps into the main menu, with various death sounds playing on exit. Good, solid fun with a simple level editor, too.
A solid, very traditional adventure game with excellent voice acting and some great writing. The puzzles are usually logical, but some suffer from only having one (very linear) solution, occasional pixel-hunting, etc. The Broken Sword series is about the only adventure game franchise that measures up to Lucasarts' heydey, so if you're looking for a Fate of Atlantis-style adventure game, that's pretty much what you get here.
Played Exoddus on the Playstation, and it kicked my butt like no tomorrow. Thankfully, the logical structure of level and puzzle design makes sure that you *can* beat each challenge. Rescuing every last Mudokon, however, is clinically insane to attempt without a walkthrough. The oddball sense of humor is sometimes fun, and sometimes jarring. Still, nothing else looks or sounds like Oddworld games, and that's ultimately Exoddus' greatest strength. Oh, and no box puzzles. That's definately a plus. :)
The tech behind Fallout is definately a little long in the tooth at this point, but the range of playstyles and excellent writing still make it one of the best RPGs ever made. The turn-based combat takes a while for some battles, so equip yourself well and be patient. The ending alone is worth taking the trip.
