Verdana is an attractive font that uses large lowercase letters to appear more readable. It was made famous on www.amazon.com. However, it's a little larger than other fonts, so you'll usually use it at a slightly smaller font size (as shown here).

Georgia is another nicely readable font with large lowercase letters.

Tahoma is the Windows system font, which also turns up on the Web (see www.msn.com).

Comic Sans is a very informal sans-serif font with soft, rounded edges and dark letters.

Arial Black is designed for extra-bold headlines that stand out.

Impact is another bold headline font that has narrow, square letters.