There are thousands upon thousands of fonts out there. By some estimates, there are over 55,000 fonts available and not all of them are good looking. In fact, some are plain ugly. This post is certainly not an attempt to judge what fonts are the best and what font are the worst. In many cases, fonts, like a music background in a movie set a mood for a poster, an advertisement, or a website. A font reminiscent of a future world would look very out of place when used for a Renaissance Fair. A decidedly western font would look equally out of place in an advertisement promoting a trip to China.
Even putting aside decorative font styles such as those listed above, picking the right font for your project is very important to get the mood as well as the point across. The folks at Gut Feeling put together this infographic that explains a simple rule about the legibility of fonts, the Ll1 rule.