I'm not sure if I'm too late, but if I'm not I can only recommend picking up all the RPGs for those systems. Other than that, I don't really know all of the expensive titles. For DC I know Power Stone 2 is worth quite a bit, and SNES has several expensive games, but other than those I'm not sure if any of them are really worth more than 10 bucks.
SNES games worth something:
AeroFighters (right guys?)
International Superstar Soccer [Deluxe?] (NTSC version of course)
Fun 'n Games
the Extertainment games (2 of them, don't remember the names)
PS1:
X-Com: UFO Defense
That's all I can think of, never really checked prices and rarity for those consoles