Cream of the vintage crop? A very subjective question. However I don't think that there will be much disagreement with these choices: (Yes I know some of them are base radios!)
Trams of course. Why? In a word, overbuilt. Pick one up and you can feel the quality.
Brownings. Need I say more? Okay, the Mark IV was problematic but when they worked, they worked wonderfully.
I've said it before: Pearce-Simpsons. If you couldn't afford a Tram or Browning, this was the next best thing.
The old 23-channel Sonars had a great sound to them and IMO are a worthy addition to any serious CB collection.
I'm told that the Demco Satellite (all 5 pieces) were a force to be reckoned with but in over 40 years of CBing I've never heard one on the air.
Johnson Viking. When you want to totally dominate a channel. If you've ever heard one on the air, you won't forget it. If you haven't, you have no idea of just how good AM can sound.
On to the more esoteric:
CPI: Seriously now, was there anything more advanced for it's time? They looked and were built like nothing else. 100% made in USA. Could there be anything better?
Well, yes...
Was the Stoner the best CB radio ever? Tough call. An SSB-only radio that cost more than anything else on the market? Definitely not for your average CB'er. They had to be doing something right, pristine examples still bring four figures on the used market.
Lesser known but still a major contender was the ARF 2001. Talk about advanced for it's time! Who the hell knew what a microprocessor was back in the 70's? Damn fine radio.
A friend of mine had an old Demco and it was a super rig! great audio on both RX and TX.... must be the tubes! I have two HyGain 623s with a tube final, TV sweep tube I think. Cannot wait till they are up and running!
73 mechanic