One more consideration regarding how to get to your final game list.
Let's assume that you want to end up with a
huge list of 1000 that doesn't include crappy bootlegs, games like Thayer's Quest with controls that you can't duplicate, and games that aren't working yet in MAME.
Which is easier, counting
up from 0 to 1000 or counting
down from 20,000 to 1000?
The math works, even with a
crazy game list of 2000 where you spend more time scrolling thru the list than playing.
IMHO it's better to add diamonds than subtract coal. YMMV.
The "All Killer, No Filler" game lists
here are a solid starting point.
Scott