Opera is good--good enough that I shelled out $40 for it, after using Firefox since before it was Fire
bird. There are things about Firefox I miss, but Opera is much faster, especially with many tabs open. 8.02 has fixed the bugs that plagued earlier versions, and it runs everywhere. I use it only on Windows and FreeBSD, but a single license gets you keys for many platforms.
Opera has pretty good RSS support, too, although I use another reader.
Both Firefox and Opera are much better than IE, for many reasons (and I'm not your standard-issue MS basher--I make my living writing software for Windows, but I just don't like IE).