I think it's really down to Orange for most people; they have the full "Terror" line, which caters to any taste and fits into most people's budget. Great amps with very good value.
Other than that there are only the Mesa (which cost a lot more) and there's the new Carvin Legacy 3, which Guitarist loved. I have listened to the video they provided and it really sounds great, but I have the feel that it's not really a "low power amp".
But for me personally the only options that fit in my budget are the Orange Dark Terror or the Jim Root one.
One more thing:
Watts and Volume is a tricky thing. I got some really good tones from my 50Watt JCM900 combo at low volumes, simply because the master volume worked quite nice. On my 20Watt Krank Rev Jr I struggle with that much more. It does depend not just on the watts, but really quite a lot just how the pots work and how the amp reacts to that. I also always felt that the cab and the speakers can make quite a difference in volume.
