Rheem/Ruud, model RGRA/UGRA. It's been on the market since 1994 and is one of the best in terms of reliability. Also at only 34" in height it is user installer friendly too. Stainless steel primary heat exchanger with lifetime warranty to original owner and spark ignition. They also make a 2 stage version model RGRK/RGRL if you live in the north country.
Premium unit of whichever brand. All 3 have low end and premium. All 3 low end outdoor units are cheaper built and noisier. All 3 premium outdoor units have all the bells & whistles and are quiet. Install being equal I'd probably go Amana myself but wouldn't be bothered by a good install of any of them. But getting the good install may be a challenge these days.
Just York in general. I have worked in a pair of supply houses over the years, and the biggest complaints come on York and Lennox as far as reliability issues go and what I have sold parts for. Trane, Carrier(ICP Tempstar, Heil, etc), and the Amana lines seem to have better quality products. If the Affinity series is better, then thats great and I hope York goes far on it, the units I am speaking on are ones that are in service right now.