By the time I weed out the Mahjong, gambling, adult, non-working, and unwanted clones, I end up with around 2,500-2,800 games (don't remember the exact number right now).
At 14,000 you're probably going to have a list that is 80% crap you don't want anyway.
There are some worthy clones (pacman is a clone of puckman), but I don't like them all showing.
Once you get a little more familiar with all this emulator stuff, check out romlister to weed out stuff you don't want.
http://www.waste.org/~winkles/ROMLister/