I bought an xbox a couple of years ago and bought a 300 gb hdd for it and my friend modded it for me so now i got like 70 xbox games, 7 emulators with thousands of roms, media capabilities, and i can watch youtube on my xbox!
i dont have a 360 but one of my friends softmodded his so that he could dll games and burn them onto a dvd and play them even with live. he got gears of war 2 before it was even out lol
I just bought an xbox the other day for $50, I'm in the process of modding it right now. Should be pretty great. Will be able to play N64 and PSX emulators, watch AVIs, listen to some music, browse the internet. All that good stuff. :)