Whoever says Linux isn't a good platform for gaming is only half right (for now). While Linux may not have a very robust lineup of games that run natively, there are still options out there for creating a great gaming experience!
Intro to Gaming Platform Emulation
When I talk about gaming platform emulation here, I'm talking about running games on your Linux machine using software that simulates the environment the games would otherwise run in natively. The type of emulation software you use depends very much on the type of games you want to play.
Below, I'll describe the best (in my opinion) game platform emulation software available for Linux.
Ah, DOS. You gave birth to many a gamer, only to vanish with the emergence of pretty little windows and true color displays. Lucky for us, we can relive our faithful DOS gaming days with a little app called DOSBox.
DOSBox (http://www.dosbox.com) provides everything you would need for a complete DOS-based gaming experience (trust me on this). It's also being actively developed, so you can keep up with all the latest features if you'd like.
Being eaten by a grue may send you into a nostalgic seizure.
Sega Genesis / Mega Drive Emulation
There are many choices for emulation of this platform. Fortunately, the folks at GerbilSoft made the choice of emulators an easy one.
Gens/GS (http://info.sonicretro.org/Gens/GS) is GerbilSoft's fork of Gens, and man does it rock. With each milestone, Gens/GS becomes faster, more stable, and more feature-filled. Best of all, it's open source!
Go ahead and play your naughty 16-bit games. I won't tell.
Super Nintendo Emulation
When bsnes' big brother ZSNES stopped working with my PulseAudio setup, then wouldn't compile on my system, I was completely lost. Luckily, bsnes was there to tell me everything was okay (and it was). It is decently fast, works with my audio setup, and has every feature one would need to enjoy your SNES games again without fishing your old console from the closet.
Unfortunately, I can't whip up a screenshot right now because of some problems bsnes is having with one of the Gnome dialogs. Hope I don't have to second guess my decision . . .
Nintendo Entertainment System (NES) Emulation
The winner here would have to be FCEUX (http://fceux.com/web/htdocs/). It's a great emulator, though the lack of a GUI is kinda off-putting. There are GUI frontends available to make the emulator friendlier for the casual gamer however.
Make no mistake, this emulator is quite complex. A visit to its homepage will show you that. But with the right choice of GUI, you'll be playing Super Mario Bros. and eating mushrooms in no time.
The choice never gets easier . . .
Rounding things off in the Nintendo emulation department is the greatest N64 emulator for Linux to date. Mupen64Plus (http://code.google.com/p/mupen64plus/) stole the best emulator spot with its great list of features and compatibility. It plays most of your backup games quite well, and has an active community.
The above list of game platform emulation software is not exhaustive by any means. I plan on contiuing this list at a later date, with entries for NintendoDS, GameBoy, GameBoy Advanced, MAME, and of course, Windows emulators.