pinworm

That depends on where you go most of the time, and where you are based.

For domestic I perfer USAirways, their benefits are pretty good, and they have international routes as well, so I can get upgrades on international flights.

I also travel to the UK alot these days, so I have begun spreading it around to VS (Virgin Atlantic). Slower program, but as I go so often it is building up and their F class is quite nice with the lie-flats. Virgin America points also add up, so I sometimes take their domestic routes.

I used to take WN (southwest) when I was based in PHX. It's a real peasant, cattle car of an airline with a lackluster awards program, but the benefits are rather quick..if you call first crack at a coach seat a "benefit". But they are good for short haul domestics and have a pretty good routing system. If you need a quick run from SAN to OAK you might as well go with them..keeping in mind that any awards you get will not be any good for international travel. They have no bag fee and no change fee (provided you change to a flight of the same fare type, or you pay the diff)..but I never check bags and I rarely change flights and you will have to consider your own situation. Remember, many of the others will also wavie bag fees and change fees at a certain status level. Card partner is visa, so if you have an amex or MC you cannot pull the same benefits.

If you are going to or from DEN most of the time, have a look at Frontier. Smaller airline, not much to say about their awards programs, but generally a good airline. Also consider United, especially for DEN. Their program is quite good IMHO, especially in the mid-tiers.

I also have status on CO due to an old route of mine involving monthly trips to Houston. Nasty crews! Lackluster program.

AA is still a good one, and I have always liked them as an airline. Most of my status with them was earned over 10 years in dribs and drabs on Intl' Heavy to South America and American Eagle commuters during the 80's. Since I moved to the southwestern corner of the country, I don't get on them much anymore.

As you are going out of ROC, you may want to consider AA, US and UA. Their regional carriers may serve that airport and then you can book one itinerary all the way through and earn points on the commuter flight too. Join them all, then book based on scheduling.