Atlanta's one huge success with transit that it doesn't get enough credit for is that it connects directly to the airport. So many other cities with "better" transit have complex schemes of switching between different buses operated by the airport authority and the city before you can get to the main system. In Atlanta you simply go over to baggage claim and the train is right there.
Too bad they screwed this up when they built the International Terminal, which is connected with a bus on surface streets that gets stuck in traffic and at lights. If you're flying an airline with a presence in the domestic terminal, you can use the internal transit system to get to the International Terminal but otherwise you're stuck switching from the train to the bus or vice versa. It's an annoying bit of extra friction that shouldn't exist.
Atlanta’s huge success is that the trains run on time and they have been able to maintain the automated train control. Atlanta doesn’t get enough credit for being a blue city that actually does some basic stuff right.
Portland, Salt Lake City have pretty good connections. Seattle also if you don't mind walking through the parking garage (often security will snake back to the lightrail station, you know you are in for a bad day). SFO has Bart to the airport, Caltrain is also possible but you have to connect to Bart for one station. I admit that I've been to SFO a few times and have never bothered taking Bart (in contrast, I always take Max from PDX).
Too bad they screwed this up when they built the International Terminal, which is connected with a bus on surface streets that gets stuck in traffic and at lights. If you're flying an airline with a presence in the domestic terminal, you can use the internal transit system to get to the International Terminal but otherwise you're stuck switching from the train to the bus or vice versa. It's an annoying bit of extra friction that shouldn't exist.