Old school Xbox = MAME machine!
I have been meaning to get an original Xbox for this exact reason. I have the X-Arcade dual arcade stick with Xbox/PS3 adapter ready to go, just no Xbox. The Goodwill near me has 3 of them but are trying to charge ebay prices for them. Just waiting for a good deal on one to make it my dedicated MAME machine.
I have 4.
1 I know works, 1 I know works but has some problems, The other 2 are untested. I've been meaning to mod one myself just haven't gotten around to it yet and am a bit afraid that I will screw something up.
(Yes wiggy, I know I've been talking about this forever. Ha ha.)