Where can I find fonts (preferably free, but a reasonable fee is acceptable) that I can use in my for-pay/commericial game?
If you're building a web game, Google has provided free fonts here: https://www.google.com/fonts This is a great service for web developers, because web licenses for fonts can be a gray area. They have only a small fraction of the fonts you can find on sites like others have suggested, however.
I always head to dafont.com, although the range is similar to Font Squirrel and MyFonts.
Fonts from Canada Type have a reasonable license, and I plan on using at least one of theirs in my next iPhone game.