I've used IE, Mozilla, Opera and Crazy Browser (which basically just sits on top of IE).
Of them all, I really like Opera the best. I have the free version so I get the ads, but it just goes against the grain to pay for something when every other comparable product is free.
I've never had a problem with Opera crashing (within Win XP Pro) but I must admit it's not compatible with a few sites or Forums. My favourite part of Opera is the way the bookmarks are arranged, nothing else comes close, imo.