Xbox
Original Xbox Mods
The original Xbox is a highly customizeable console & is similar in architecture to a desktop PC.
Project Stellar/XboxHD+ is a digital to digital HDMI mod that outputs 1080i video and is 5.1 surround sound capable. It also includes a mod chip.
The Hard drive interface can be upgraded via a SATA adapter and an 80 pin IDE cable, which will increase hard drive read/write speed.
There are also various mod chips still in production that can add increased functionality and region free capabilities.
A clock capacitor removal is advisable on all Xbox units as it will eventually leak and cause damage to the motherboard.
RAM Upgrade
The Xbox ram can be upgraded to 128mb. While there are certain patches that allow mainline Xbox titles to utilize the extra chips, the true benefit of this upgrade is for smoother emulation of the various emulators available on the platform. It also will allow you to emulate Sega Chihiro games.