I just modded a 1.6 Xbox with the Ndure exploit. Comes with one S-type controller, AV cable, power cord, box, manuals. I'm asking $150 plus actual shipping (PM me zip code for quote).
I preloaded it with all my favorite programs:
* UnleashX dashboard - includes game save downloading, custom skins, and ripping games from xbox discs.
* Xbox Media Center - plays almost any type of audio and video files, including DVD's without buying a dongle. Play online games without a Live account with Xlink Kai. Loaded with CNN streamer so you can watch the news from your xbox.
* Final Burn Alpha XXX - emulator to play all your favorite CPS1, CPS2, and NeoGeo arcade games. Would play MvC, SFA3, Super Turbo, Garou: MOTW, all King of Fighters, etc. Of course you have to own the arcade boards to legally use the roms.
* xSNES9x - emulator to play all SNES roms. Same disclaimer as above.
* DVD-X2 - an alternate DVD player if you don't like the XBMC version.
The hard drive is stock, but it still has over 3 gb space free, so you can rip a few games, load it up with ROMs, video, music, or whatever.
I set it up with dual-boot. If you power it up with the eject button, it boots to a Live safe Microsoft dashboard. If you power it up with the on button, it boots to the modded UnleashX dashboard. If it is powered up to a modded state, it will block access to Live so you won't get banned. You can also turn it on with a game disc in the drive and it will boot directly to the game, bypassing the mod.
I highly recommend buying the game Splinter Cell (the first one) to get full administrative access to the mod. It is not necessary but it is good to have. Splinter Cell costs $7 at EB Games.