Most important would be A: durability, B: comfort of use, C: has good lenses available in the focal length(s) I want to use, D: built-in metering. Not necessarily in that order of priority. Certain features would on a case-by-case basis override other features, like I'd trade a little durability for mind-blowing optics, or give up an internal meter for something that is more comfortable to hold in the hand. Doesn't matter if it has 20,000 point multi-evaluative matrix metering if there's a 50/50 chance it'll be pointing at the floor or ceiling instead of what you wanted to photograph because the camera is too small/big/slippery.
On that list you provided, I'm a big Contax fan for the optics. I used to have a 167 MT and an RX. Beautiful cameras that were intuitive to use and had some of the best glass going. If Contax glass is in your budget, I'd also look at older Leica SLRs - an R6.x or even an R7 would be a good option and unlike their rangefinders, the Leica SLRs and lenses are actually affordable on the used market.