Good question. I’m struggling to think which airports I’ve stopped and thought “Man, this is a great airport” and why.
San Francisco did make me think that, but I suspect it was partly the approach and the design of the buildings.
I liked O’Hare a lot, mainly because of how easy it was to connect to the rest of the city, without any “walk 20 minutes this way, cross a highway, wait in a place that looks dangerous” nonsense. I had another friend tell me recently that she hated O’Hare because it was hard to navigate, but I didn’t experience that at all. I found the staff very friendly.
Most of what I appreciate in an airport is the ease of getting from gate to gate for connecting flights. The absolute worst that I’ve experienced have been Heathrow and Pearson (i.e., Toronto). Pearson also has incredibly shitty customer service. It’s my most hated airport, and I’ll avoid it as hard as a connection through the US if I can.
Some airports have a lot of fussy connections between gates (underground trains/shuttle buses, etc.), but if they are fast and efficient (and easy to figure out), I don’t mind any of that. Zurich is that way, and there’s another I’ve experienced that can’t think of off the top of my head.
Teeny tiny airports can be fun – you never get lost, and people are nice. The Calgary airport is so small (for a city) that it can’t help but be incredibly straightforward, though the décor is a bit hokey. There’s always a trade-off, I guess.
Restaurants in airports are universally terrible. I avoid them when possible, unless I can’t plug in my laptop at the gate. Okay, you might have a shot at some decent food in a teeny tiny airport.
I almost never arrive early; I’m that person whose scarf is flapping wildly behind as I run from check-in to security to gate, muttering and cursing the whole way.