I like Chrome, the url bar at the top is really intelligent...u type 'sc' and press enter and it goes to www.scirra.com
if u've visited it before
Firefox 3 requires u to click on the dropdown list. Also it seems to have google search built into the address bar. Like for instance, type in 'doppel', wait for about half a second, and google search results appear in the address bar as well as 'did u mean...' etc etc.
Also I like how the tabs appear in the title bar, it saves a lot of room.