My favorite fonts are Arial and Verdana. Check out also this font site http://www.dafont.com/top.php hope it helps.
That si a very difficult question to answer. A font is often associated with a type of topic. You have business fonts, comic/humor fonts, movies etc. As "geekos" said, Arial and Verdena are som good ones and commonly used.
, If you want a readable font for web or print. You can use arial, helvetica, verdana. If you want to have a comic strip design, you can use comic sans. If it's Christmas time, try using scriptina. All fonts have different ways to use. Just use your instinct if the font you will use fits to your design.
Pretty ambiguous question, along the lines of "What's the best food?", "What's the best car?". The issue is in what context? There are many fonts and each of them have their place, but ultimately it comes down to preference and context. If it's a website, then you want to go for something that is very readable. If it's a design for an image/logo then you can be more creative and use different fonts. Sometimes I am amazed at the sheer lack of thought that goes into the questions on these forums.
Verdana is the best at eating ham sandwiches, Arial is the most flirtatious and Cabin is well, the geekiest! Yes Gwiz, ambiguous !
I think any font that is gaudy is best. Everybody uses Arial and Verdana. Stand out in the crowd dude! And avoid using any TrueType fonts. They are for woosies.
I would try to look at humanistic sans-serifs fonts for web use. They are the easiest to read and will generally render well in most web browsers.
I'm using Knockout a lot recently, as well as Gotham Rounded, but it depends on what sort of design you're creating really. Each font gives a different appeal, and that appeal is what you have to match to the purpose or scope of the graphic/website/content you're creating.