I am an Alaska Airlines very frequent flyer- Seattle, where I live, is their home base and I preferentially take them when I can. Their planes are all 737s, much of the fleet has been updated to 737/800-900 series, which have more room in coach class. Flight crews are friendly, the airline recycles.
Food is, well, airline food. I personally buy something great to eat at the airport or the local organic grocery and bring it with me, as even first class/business class food mostly sucks these days. But for good service and mostly on-time flights (this, of course, excepts the day that six of us, including Grethe Cammermeyer and her partner, were all stuck in Seattle trying to get to the Mexican Riviera cruise last March because the entire system computer was down- but that was the exception to the usual for us), Alaska ranks high for me. I occasionally still fly the former Northwest (now Delta), or American, because of destinations to which Alaska doesn't fly, and am always impressed by how well Alaska stacks up. And oh yeah, they have a very strong LGBT friendly diversity program, at least here in Seattle at their home office.