Wow, good link Keithjr, and happy birthday too
. From my experiences with emulators, FCEUltra is the very best one on every platform, including Xbox. However, it's very poorly documented and a lot of it's docs are in Japanese.
But, you can find rpm binaries here:
http://rpm.pbone.net/index.php3/stat.../idg/Emulators
it's mostly for Mandrake, but I got it to run under Slackware, Sun JDS and SuSE 9.1 and Libranet without a problem. In the case of Slackware or Debian, you might want to convert those packages to their native ones (.tgz for Slackware or .deb for Debian/Libranet). This is easily done with Alien or rpm2tgz. You could force a rpm install in Slack with "--nodeps" flag, but that's unnecessary.
For Snes, zsnes kicks arses. It has a nice gui and emulates Snes accurately. Snes9x is a great second best and run from the command line or with a gui as snes9express (very buggy). A little sound distortion is found in games as Megaman X, Super Street Fighter and special chips as C4 and FX can be weird too... Snes9x is also relatively faster then Zsnes in older machines from my tests. The Xport for Xbox of Snes9x is just impressive and the sound issues were worked out.
My only tip is, do not try to compile FCEUltra or Zsnes. They seems to compile randomly, specially Zsnes. Get the binary, convert it or install it. It will save yourself hours of work and avoid you to tear your hairs apart...
Good luck!