They do look good, and for arcade/mame they would probably be perfect. I'm planning on getting a pair of the akuma controllers for trying out, since they are designed originally to work with the Xbox with no special adapters needed. Sega did re-release the saturn controller for the PS2, but it never made it to the Xbox. However, with a PS1/PS2 controller adapter for the Xbox, it should work in theory. This would probably be the best controller option for Genesis games, and would work for NES games as well. However, it would probably work poorly for SNES games since the 2nd row of 3 buttons on sega controllers were so much smaller in size than the first row of 3 buttons. So, no matter how you mapped the buttons in the emulator (presuming it works with a PS1/PS2 to Xbox adapter in the first place), there is no way to get all 4 buttons used on the SNES pad to be quite accurate using a Saturn controller.
I think, from what I can tell, short of hacking apart an s-type Xbox conroller and doing a lot of wiring/soldering, the Street Fighter anniversary controller would probably be the best choice. You get 6 buttons that are all full size, and triggers, so this should work perfect for NES/SNES and Genesis emulation. So, once the ones I ordered arrive, I'll know if they are worth it or not. Some reviews I've read on them claim their are made cheaply and break easily, but for $10 a controller, it's not a big loss if that happens.
However, I do see one primary controller area that is still seriously lacking, and that being the Nintendo 64 controller. It was designed and shaped so strange in comparison to any controller seen before or since, that I think you'd actually have to do some intensive wiring/soldering and hope for being able to get an actual N64 controller to work on it.
I realize this is probably a common complaint by users of emulators on the original Xbox, but the lack of any directly viable option for using original system controllers is a real pain. Sure the original NES controller was about as far from ergonomic as you could get. Sure, your fingers would cramp after enough button mashing. Sure, its small by comparison to most all modern console controllers. However, it is the only way to play NES games with the original feel, response, and control.
I guess this is just another reason for frustration, considering that the Xbox was not designed to be capable of using plug-n-play. I've seen a really cool website where you can buy original NES and SNES controllers, for example, that have been modified with USB connectors on the end that are completely plug-n-play compatible with windows based PCs. Its a real shame that such functionality was never a part of the original Xbox. It's also a concern of mnie.
If that functionality was not built into the original Xbox, even if/when the 360 gets hacked to run unsigned code, would it be capable of using original controllers modified to USB anymore than the original Xbox can?
I realize that neither PSone or N64 games will likely ever run completely flawlessly in emulation on the original Xbox, but the 360 should easily have the hardware power necessary to do so. I just hope that if/when emulation moves onto the nex-gen console, that the lack of original system controller support doesn't ollow along with it.