Compulsive font browsing: FontExplorerX

The best font browser I met at this time: Linotype FontExplorerX. I'm playing with the Mac version and it rocks! Top features:

• Can visualize non-installed fonts.
• Many font formats supported.
• Displays a whole font family at once. Also recognizes Optical fonts.
• Sparse selection for multiple previews. Supports multiple windows for font detail. That's incredibly useful for comparisons!
• Rich preview options, like custom text and ligature activation.
• Detailed font information with huge zoom factor, baseline display, x-height and bouding box.
• Unicode support.
• Virtual font folders.
• Detects font conflicts.
• More than font viewing: may intercept system calls to obtain fonts from some applications like InDesign or XPress.

It's a commercial product with an option to buy fonts on Linotype's site, but it is downloadable and usable for free. It's a beautiful professional tool. Real font lovers like me will find it more addictive than YouTube!