I don't know which is useful:
IE6: Not safe.
IE7: Needs WGA - Windows Geuine Advantage and it has compatibility only on Vista and XP SP2.
Firefox: Read this.
Opera: Not compatible with all web pages.
Safari: Now supports Windows, but I don't know anything about it.
Netscape Navigator: I don't know anything about it.
Crazy Browser: I saw that browser in magazines, but it seems unpopular. Does someone know this browser?
If you got some sources about browsers, you could add a link to it (if administrator of this forum allows).