The best strategy with flying I've found is to pick one Legacy carrier/alliance if you're a frequent traveler (because they treat their folks with status quite well, at the expense of everyone else). If you don't fly >25k miles/year, do what you do.

Pretty much this. Pick an airline based on convenience, and sign up for the frequent-flyer program.

So many of the negatives associated with air travel typically boil down to shopping based solely on base price, with zero brand loyalty, and then being surprised that the airline doesn't treat you as well as a repeat customer who buys (or has an employer who buys) full-fare tickets. And so much of the difference between the full and discounted fares typically gets made up one way or another; either you're paying about the same as someone who bought "discount" but now is getting socked with fees left and right to check bags, use power outlets, etc., or often it just evens out over the course of enough flights.

I'm a Gold member on United, and Silver on Delta. United treats me fairly well [when they have an issue they pass me on to US Airways]. I've had massive issues with Delta.

Honestly, I'm not thrilled about Southwest. They'll get you there... but eh.

I have flown pretty much all the legacy carriers, including the ones that merged out of existence.

Delta is by far the worst I've dealt with. No other carrier even comes close on that score.

I'm currently with US Airways (Platinum) for various reasons; they've treated me pretty well, their hubs are decent enough, routes are convenient, and they fly real planes rather than cramped CRJ lawn darts in and out of my home airport (Kansas City). And it's comforting to know, at the moment, that if they do screw up horribly I have other options within the alliance, though the looming prospect of the AA merger is going to lead to some serious thinking about whether I should just do it pre-emptively.

Among the low-cost carriers I don't mind Southwest so much. They're kind of the Chipotle of airlines; you know what you're going to get, you know it's not the greatest but also not the worst, and they have some quirky branding and service aspects that inspire loyalty among their regular customers. If I were going to fly an LCC, though, I'd probably pick Frontier just because they give a bit more bang for the buck on the routes I'm most likely to fly.