For SNES you'll want to get SNES9X TYL++ by Ruka, it's Slim or Go only and is the best SNES emulator by far.
Get the latest PSX2PSP program. It's the best PSX eboot creator and lets you see what your eboot will look like with the background and pic prior to creation. Also the easiest multi disc eboot creator. One thing you want to make sure of is that even though the region codes codes(SLUS, etc) on some games are different, like Suikoden 1 and Suikoden 2 have different codes, make sure you give them both the same code. The reason for this is because each code creates its own memory cards and Suikoden 2 won't be able to find the Suikoden save data if it's a different code because it's a completely different card. When creating a multi disc game it really doesn't matter though since the multi disc game will be one card as well(I think.)
To rip PSX games you'll need a program that rips all data from the PSX disc and not just a portion. There is some data from some games that won't be ripped and music won't be played. Only from games that you can listen to the music on a CD player, that specific music won't be ripped for some reason or if it is just won't work.
The best Genesis emulator which can also play Sega CD well, aside from a very few games, No Dark Wizard unfortunately
, is the newest PicoDrive.
EmuMaster or the older version, Masterboy, are the best Gamegear, Gameboy, and SMS emulators.
The newest GBA emulator you can find is probably good. They used to crash on games like Fire Emblem and Kirby's Nightmare in Dreamland, but they all work fine now.
Don't remember what PC engine emulator I use, but I know that I had two, both of them were very picky on getting TG16CD to work. Not worth the hassle of getting CD games to work honestly.
MVS2PSP and CPS2PSP are two programs worth getting for Capcom arcade games and Neo Geo arcade games. Full speed on all MVS, CPS2, and another one I can't remember the name but CPS1 systems, but maybe called CPS1PSP? You'll have to look around. Make sure to get the one that has adhoc because you can play the multiplayer games with another PSP if they have the game as well. Every emulator comese with a cache.exe which you need to create cache files of every game above a certain size in order to play. Every new version you need to create a new cache file. If you have MVS2PSP 2.2 and then you upgrade to 2.3 or whatever is next, the same cache file won't work. You'll have to redo it.