Sometimes, it’s the little things.
I love that Firefox shows you the title of the last time you loaded a URL – it makes it much easier to tell which page is the one you really want. Like the “crosscity.com” entries below – without the title, I’d have to load each before figuring out which one was the one I wanted.
No such luck in IE7, though – all you get from the completion list is the URL itself.
One other point (not a feature I miss, though) – you’ll notice that in firefox the favicon (just to the left of the address you’re typing in) immediately blanks once you start typing – IE7 doesn’t do that, so while I’m about to go to a microsoft site, the favicon is still Google’s (see above).