Complicated question, seeing the range of amps you mention.
The ones I know or know a little:
Little Bastard 30: Admittedly has 30 [b]valve[/b] watts, but still only 30 watts - not 500. Can you live with that?
IMHO it's a far more refined amp than the Terror Bass (I have both), and once you know the EQ, it's versatile. Where the OTB is a rocker, to me the LB is more of an Eric Clapton, if you get my drift.
MAG 300: from comments here, apparently a little marmite (veggiemite?), but if you're willing to dial, it has a good EQ where the sweeps are very important. Not a stand-out amp in my book, but will get the job done in many different styles. Apparently must not be combined with the MAG 410. Compressor usable - not more. SubOctave usable only on long, long tones.
BH500: well-sounding but maybe slightly anonymous. Very versatile. IMHO a great SpectraComp compressor and great ValveTone. I'll probably get one in addition to the others, just for the heckfun of it.
All the others seem to come highly regarded, but I haven't tried them.
Good luck!
best,
bert