Modding your Xbox gives you access to an astoundingly more valuable product than something to just play Halo on. There's a huge variety of programs available to you, and all of them are available on the internet. Almost every emulator supports up to 720P resolution, meaning next to the Wii, the ideal way to play old games on an HD set. Can even use a scanline filter if you really want to.

Be careful what you delete on the Xbox, because it has the possibility of bricking it. If you do happen to brick the xbox, a modchip will bring it back to life. A modchip also makes it much easier to install a bigger harddrive. A normal xbox has a 10GB harddrive, which can fill up plenty quickly. Xboxen will accept most 3.5“ IDE drives.

A Dashboard is comparable to an OS. Allows you to access to your Xbox by FTP, browse your Xbox harddrive, and launches any of the apps, games, and emulators you have installed. This is what will boot up instead of Xbox green menu.

• EvolutionX
  • If you follow DeusJester's guide, this is your new Dashboard. Not much to look at, but allows you to easily FTP and launch things.

• Xbox Media Center
  • Probably what you will want to make your default. It plays just about every video file in existence, has a fantastic XBox 360 Blades skin, and now has the ability to launch games directly. Also your Xbox is now a region free DVD player! One that you can just use an xbox controller to navigate!

• DVD2Xbox
  • Rips any Xbox game to your harddrive. The game is then launchable and fully playable from any Dashboard. Also good if you can't get a burned game to run, you can still get it to rip.

• ZSnexBox - Super Nintendo
  • Almost every emulator has an ability to maintain accurate aspect ratio. The only one that doesn't, to a lot of headache is this one. It was lauded for a while as having the best SNES emulation anywhere. It's still very good, outside of a few games not working at all. The unreleased Star Fox 2 comes to mind. There's another emulator xSNES9x, that will play those few games, and that's about the only reason to use it.

• Coinops Ignite R2 - Arcade
  • While definitely the best Arcade emulator available, it also has an increasingly confusing release names. This is version on my Xbox right now. CoinOPS Re-Ignite SHOWCASE appears to be the last and latest version. The author of the emulator wasn't the best at explaining what was the difference between each version. Almost every 2D game released in arcades will play at full speed and sound barring a select few. Those will play without sound.

• Final BurnAlpha XXX - Arcade
  • Coinops is a MAME catch all emulator. However FBA is designed for CPS1, CPS2, Neogeo, and Cave/Psikyo shooters. The emulator already has the controls set up for a reasonable human being, and are easily changeable. Roms that work on this emulator are hard to find outside of the convenient torrent that contains the emulator and every game it plays. This torrent will give you a hundred clones and hacks you'll probably never want to play, but I'll leave that to your discretion.

• CPX3 - CPS3
  • Plays all 6 games released on Capcom's CPS 3 arcade board surprisingly well. It has some shadow problems with SF3:2, but Third Strike is just about perfect (for using an xbox controller at least.)

• KI-XXX - Killer Instinct
  • Experience 100 hit combos again! While usually lauded as something a modded xbox can do, I wasn't very impressed. Frame rate stuttered like a underpowered computer and less like a prehistorically impressive fighter.

• Surreal 64 - Nintendo 64
  • There are two versions of this recommended Beta 5 and 1.0. The developers never released the source and disappeared, so gamers have been crushed for years. Some games play surprisingly well (1080, Waverace 64, Mario 64, Sin and Punishment) and the games that gave Windows based emulators problems give the Xbox problems. Surreal is 3 emulators in 1 and has a variety of settings, so there's a possibility voodoo will make your game work well. Majora's Mask worked great until it froze on me at the same spot twice. Better off buying a real N64, or hoping Virtual Console gets on the ball.

• mednafenx_nes - NES
  • Since NES emulation was perfected somewhere along 1996, this has never given me any problems.

• mednafenx_pce - PC Engine/Turbographx
  • Excellent PC Engine emulator. Very good PC Engine CD emulator too, but incredibly finicky about file names. I still haven't got Y's to work on it.

• NeoGenesis - Genesis/Megadrive/Sega CD/32x
  • The default skin for this emulator is obnoxious! If you can't find a better one, you can at least easily delete the mp3 for it. Works fantastic, outside of save states for Sega CD games can cause problems. If the games keep a save file on a real Sega CD, it'll make one here. It's also easy to switch out or mix and match the US and JP Sonic CD soundtracks.

• neopopx - Neo Geo Pocket Color

• XBoyAdvance - Gameboy/Color/Advance
  • The Gameboy and Color emulation is great. The Advance emulation is fantastic for most games, but some are just unplayable (anything that has Final Fantasy in the title.)

• pcsxbox - Playstation 1
  • Somewhere between Coinops and Surreal is pcsxbox. There's not a lot of documentation of what changed between versions, and some games play better with different versions. I've managed to get through Symphony of the Night, and most of Crash Bandicoot 2 on my version. Says 1.5. There is a compatibility list, but I've found it mostly useless.

• ScummVM - Scumm
  • Any Lucasarts adventure game is at your disposable.

• x68000x - Sharp 68000
  • Confusing to use, but runs ChoRenSha68K in all it's glory.

Each of these plays near perfectly.

• Cave Story

• DoomX

• rRootage

• StepmaniaX

• xDuke - Duke Nukem 3D

• DeusJester's excellent softmodding guide
• Help Persona softmod an Xbox thread
• A full list of emulators
• Guide to setting up your xbox emulators to PIXEL PERFECTION. Good resource for XBMC icons too.