My vote goes for mednafen (here's hoping they'll import genplus-gx code for perfect Sega Cd emulation for once). It's got the bsnes core for snes (not the newest), and everything just works great (use ultra low buffer setting for sound and everything feels like the real console; no distortion or sound lag with alsa and hardware mixing). Very similar to Mess, except everything works with good to very accurate emulation (mess has lots of drivers that still don't work too good). Also goes good with CRTs since you can use custom resolutions and keep pixel perfect output with odd ones (keep output from stretching if it doesn't match resolution too); e.g. you can use 640x240 @120hz with only width stretched x2 without interpolation, and have perfect pixels with natural scanlines on Genesis and other 320x224 native consoles (Mame-Mess does this too).
Speaking of monitors, I get natural scanlines in 320x240 @120hz currently with 8400gs, but some videocards-drivers simply force 120Hz double-scan (in this case 640x240@120hz is needed for natural scanlines); 320x224@120hz is below 31.5khz limit of my CRT, hence I use 320x240 or 640x240 @120hz and keep vertical portion centered (stretch vertical size through monitor controls so it fills screen; got to love analog CRT's for making every resolution native with flexibility and no lag). Mednafen, Mess and Mame are really good with custom modelines. PAL resolutions can be fun to play with, as well as lower SNES and playstation resolutions haha.
Haven't tried Mupen64 but I think that should be one of the best N64 emulators; if not, the best. Not sure though.
EPSXE and PCSX-Reloaded should be the most comaptible and accurate PSX emulators IMO.