If you get it from site which screaming free fonts, they're free to use.
A lot of "free font" sites have rip-offs of popular fonts (LOTR, GoldenEye, etc), which is obviously not legit, and even many of the so-called "free" fonts have varying licenses.
For example, some will only be licensed for personal or non-commercial use. Others will forbid any sort of modification or embedding (i.e. creating and distributing it as a bitmap font is sketchy ground).
In general, if a font's license isn't clear on a "free font" site, I'd just find a different font.
EDIT: As to the OPs question, it really depends on what kind of font you are looking for. There are plenty of free ones if you look.League of Movable TypeOpen Font LibraryGoogle Web Fonts (check license; mostly SIL OFL)PT Sans04 Bitmap/Pixel FontsRoboto (Android font)