CO's program is a joke. I've spent close to $400 right now on a reward ticket that cost 75k points. I wasn't let into the President's Club because the last leg was on an RJ. The 50% EQM thing screws business travelers. Their program will continue to get worse until it's on par with their new buddy United.

AA's program is really only good if you fly internationally and fly a lot.

AS is really your best bet. You'll be able to fly on CO, AS, NW, DL and AA and keep the points in the account. You're also in one of their hubs. I'm not sure what their fees are like, but they can't be worse than the other carriers. You'll have plenty of places to redeem the awards as well.