according to this site there are 300 essential fonts http://www.goodfonts.org/
As a web designer, you know that Verdana can get real old real fast. But you also know that there are millions of free fonts on the internet and most of them are horribly bad. Here's a secret: not all truetype fonts are bad. Some of them are quite classy. The truth is you dont have to be rich and able to afford postscript fonts in order to look professional.
I've collected 300 of my favorite truetype fonts that can be used for design works. Here they are free to download in .ttf format (works on both MacOSX and Windows machines), organized into the following categories.