Usually, the point of a combo amp is being cheap and utilitarian. Inexpensive, but get's the job done.
If what you are seeking is highest quality available in a combo format, then I'd say find a Mesa Walkabout, or Fathom/Carbine combo. There are Phil Jones, Genzler, AER, and EBS, too.
Since the above Mesa's are no longer manufactured and were quite expensive when new, used is all there is, and same for some of the combo-like GKs 3.0 10t and company. A Genzler Magellan is pretty much a combo like the old GK 3.0 10t. Then there is the upright world of Acoustic Image and the 112 Gallien-Krueger 200mb metal cabinet wonder. With Phil Jones, I've no experience with anything other than his tiniest combos, which are pricey and not much more than practice amps with great preamp and DI sections, IME.
Some combo's are just OK and not so cheap, like the wide array of Markbass and GK combos with 110, 112, 115, 210, and even 212 drivers, and then comes a herd of cheaper OK Ampegs, Peaveys, Hartke, Traynors, Fenders, GC Acoustic, Behringer, and so on, ad infinitum. At some point pretty early on, quality is kind of moot, as the quality legitimately matters less than being cheap and utilitarian. That's just how it is.
IMHO, if you find a good deal on a light high-end used cab (barefaced, audiokinesis, fEARful etc.)—just about anything besides a 410, 610, 810, or 215—you are on your way toward getting something high quality, semi-expensive/cheapish, but still having some of the appeal of a combo due to the small cabinet single driver format.
IME, all one need do is add a used micro head to a light weight used cab, and you can have a rig with all the advantages and superior performance of a high-end combo like a Mesa Fathom, but without the price. A $400 head and $350 cabinet may not sound cheap, but used walkabouts are like $800, used Genzler Magellans are ~$700, and I'll be darned if I can find a used Fathom much under $1800.