Actually, I like IE7's interface. Vastly improved over IE6.
Firefox's interface is nice and simple, but you would expect Firefox 2.0 to have some change to it, but there isn't much. Also, Firefox does crash. Trust me.
As for Opera, I've only used it once or twice so I hasn't crashed, but the interface is way too filled with features. Sure, it's nice having stuff, but the interface is bogged down with icons and this and that.
I just use Maxthon. Has the great performance of Internet Explorer and the reliability and extra features of Firefox (like RSS feeds, tabbing, themes, extensions etc.).