I mostly use stock android browser (not HTC version). Do also have Boat for when I want some more features (nice tabbed browser, but seems very marginally slower than stock) and Dolphin Mini for when I want something light.
Never really got on with Dolphin HD, though hard to say why exactly, and uninstalled Opera Mini when I realised I'd not used it for 6 months. Possible that might happen to one of the others in future, but I'm not short of space at the moment.