ZNES for snes emulation needs.
http://prdownloads.sourceforge.net/zsnes/zsnesw142.zip
Roms can be found all over, just plug in your game of choice into Google and stick the word rom after it and you will find a clean version sooner or later.
PS1 I use ePSXe, can be a bit tough to set up but works good once figured out.
http://www.epsxe.com/files/epsxe160.zip
ISOs for the games are harder to come up with then older roms, easiest way is to either use an original copy of the game, and even better rip an ISO from an original copy, reduces load times substantially.
http://www.zophar.net/ for more emulators for everything you can think of.