I use dafont.com and 1001freefonts.com. My favourite is dafont.com because they tell you if the font is for personal use only or you can use it for commercial too. That information is very important for me. So...one more vote fot dafont.com.
I have also heard a lot about dafonts from my friends.they have used it and are very happy with the variety available.you may also check out
http://www.dafont.com is the best place to go for free fonts, although some of them can't be used for commercial uses. I go there for all my font needs such as logo design, ect.
Deffinitely dafont, like someone else said its important that they let you know which ones are free to use for commercial use, or personal use which they do a good job at.