Emulation recommendations? (for ripping sprites)

Pretty soon I'd like to rip some sprites from a bunch of different games that I like across different systems. Though I will most likely be using many of the sprites on this website, there are some that are missing which I'll need to grab myself. And that's where emulators come in, and thus two questions:

1. What is the best overall emulator that I can use? Note that I want to rip sprites from NES, SNES, GB, GBC, GBA, PS2, and Sega Genesis--so mostly Nintendo systems but also a few non-Nintendo consoles. Is there a one-stop-shop emulator I can use for all these? Or will I need a system-specific emulator for each system?

2. I'm decent enough at playing video games (well, some anyway), but I can't play worth crap on a keyboard. And I know cheat codes and save states will only get you so far in certain games. So I'd like to invest in a controller adapter I can plug into the USB port on my laptop. The trouble, as above, is that there are games from multiple systems I'm looking to rip. Does anyone know of a controller adapter that's good for a variety of systems? The PS2 controller has always been my favorite, and I'd love to be able to do Nintendo games on that controller, but the only PS2 controller adapter I could find on Amazon looks like it's good for just PS2 and PS3 games. So does anyone have any suggestions?

Thanks.