Let me give out my 2 cents on this... 1. Differen't romsets, different hardware. Neo-Geo roms are either in.bin or.rom format (only.rom for NeoRAGEx,.bins work in Kawaks, Nebula and MAME). A Neo-Geo set contains P (program), C (graphics), V (samples), M (Z80 processor instructions) and S (text) roms... Sometimes there isn't an S rom because the data for S is stored in some other rom (usually the P1 rom). Now for the CPS/CPS-2 stuff CPS-1 roms' filenames might seem odd at first glance, because the filenames (inside the zip) rarely look the same. CPS games work on CPS emulators as is, because there's no encryption in them....Unlike it's big brother, which brings me to: CPS-2 roms consist of files usually named xxxx.01-xxxx.25, but sometimes the game only needs a few of these, not a full scale 01-25 and the files don't always go in order (there are cases where 02-09 files don't even exist, but the games has 10-20. In addition to the actual files, CPS-2 games need specific XOR tables released by the dudes at CPS2Shock. XOR tables do away the encryption that the game has. XOR files in the archive have an "x" as the last letter before the actual extension. If you find CPS-2 games in the 'net, you most likely notice that the archives don't have the XOR tables in them. You have to get those separately. In short Neo-Geo games DO NOT work with a CPS/CPS-2 emulator (unless the emulator has support for Neo-Geo) and vice versa. It's a completely different hardware. 2. What do you mean by this exactly? 3. Indeed, MAME is by far the most flexible emulator out there. I don't use MAME myself, but that is my choice. 3a. For Neo-Geo, I suggest that you try out Kawaks, Nebula and NeoRAGEx... NeoRAGEx is by far the easiest of the 3 to use, but it's outdated and doesn't support on-the-fly encryption of Neo-Geo games like Nebula and Kawaks. Nebula, Kawaks and MAME need specific drivers, whereas NeoRAGEx does not. NeoRAGEx has been discontinued, but several hacks from HappyASR are still 'on the anvil', so to speak. For CPS/CPS-2, use Final Burn Alpha (FBA), it also has Neo-Geo support. 'Nuff said. If you want to use just one emulator for everything, use MAME. Feel free to ask some more, if this wasn't clear enough.