Forget about any MAME newer than 0.33 or something like that. It will run like shit. 0.31 runs swell on my ex PC, a Pentium 133, but the newer ones ran like poop.
Here's the list of emus I used on my P133 (I want to put that one in an arcade cabinet!):
*MAME 0.29 (It's got Atari Tetris, what fucking else do I need?!?!
*Fellow 0.32 ... 0.33 and the FellowPR ones ran like poop, 0.32 was smoooooth
* Magic-Engine 0.92 (or something like that. The last DOS version. r0x0rz)
* ZSNES. Forgot which version, but it runs like a mad beast
* Genecyst/KGen. Genecyst was faster but KGen was not that bad eitehr and some games ran better with it.
* x128. Best Speccy emu
* Caprice32. for CPC, nothing beats this.
* CCS64 - BEST C64 em00 out there, the win32 version is pants, I always use the DOS one.
* fmsx-dos. This MSX emu is awesome.
* Other arcade emus: Raine, RAGE, NeoRage (NeorageX for Windows runs pretty well too!), System16, System8, SystemC2
If I used others, I forgot! Haven't lameulated in years