You need to check this guy out, his emulators are by far the best for android and iOS, he still hasn't done an n64 one though, and the snes one can be downloaded from his website for free at the moment...https://play.google.com/store/apps/deve ... a&hl=en_GBhttp://www.explusalpha.com/
I recommend mapping the buttons manually within each emulator and not using the archos on screen mapping. You then need to go Input/Player Mapping and switch HID gamepad to number 1, the emulator will not remember this particular setting but only takes a second to re-apply. it's to do with the way the gamepad has been made and the author of the emulators has told me he's going to fix this in an update, when he updates something, usually it applies to ALL his emulators as well
For N64 keep your eye on this guy, he's releasing snapshots for free at the moment, works great with the gamepad but some games still have issues, he's constantly fixing at the moment though...http://www.paulscode.com/forum/index.php?topic=723.0
n64oid also seems to be quite good though.