ESO is a fun MMORPG. If you like Elder Scrolls and MMOs, you will probably love this. Good graphics, fun gameplay, lots of customization options.

An oldie but a goodie. Single player RPG. A must-have for any Star Wars + RPG fans. Recently updated with Linux & Mac support, widescreen support etc.

One word. Dinosaurs! Who doesn't like dinosaurs? Great multiplayer survival game with prehistoric beasts (mammoths, dinos, and more). Supports Linux&Mac

Currently the best and only Star Trek MMO, it features both ground and space action, lots of customization, a great fleet/guild system and epic combat.