Here's what my limited research tells me:
- RAINE: Good for 2D games under-powered PCs (< 2Ghz), has some non-core features.
- Kawaks: CPS 1 & 2 (90s Capcom games) & NEO-GEO + netcode (online multiplayer)
- MAME: Resource-heavy, perfect emulation but lacking 'gamer' features - netcode, high-scores, etc. Can be compiled with expert tech.
- Zinc: Emulates System 22 games (Namco fighters - Soul Calibur, Tekken) & other 1st-gen 3D. Clunky config, good emulation on under-power PCs (< 2Ghz).
- Daphne: Dragon's Lair, Space Ace (MAME does not currently support Laserdisc games. Laserdisc ISOs are large.
- Final Burn: The Capcom fighter emu. Like Kawaks it supports CPS 1 & 2 as well as NEO-GEO but recent versions (FB Alpha) support CPS3 (Street Fighter III). Many variants supporting movie recording, cheats, netcode (via Kaillera)
- Nebula: Similar gameset (CPS 1&2, NEO-GEO + others) and features as Final Burn
- CPS3: Focuses exclusively on Street Fighter 3 and does a superb job
In essence, apart from Laserdisc games, test your game in MAME and if it's slow on your hardware, try one of the alternatives. If multi-player or cheats are your bag, you have options.
There's a very good emulator wiki
here if you need more details.
My cab has an Athlon 2800 that is a tad under-powered for 3D (possibly because it uses an ArcadeVGA card), so I use Zinc for System 22 games.