Having gotten a lot of great feedback on various programs, I'm having a hard time integrating the information to decide which carrier I ought to fly this year. I should be able to earn 27,000 eqm (at least) on UA, AA, CO, NW or DL. Which one should I pick, in your opinion, and why?

Edit: Thanks for the heads-up Kiwiflyer, I appreciate the feedback :-)

I tend to fly transcons between NYC/BOS and SJC/LAX. So pretty much all of the above serve those routes pretty extensively (with maybe AA and DL being a little more intense). I almost never buy full Y fares (I am one of those poor college students lol), and usually book through the airline's website whatever fare is lowest. As such, I never really hold out much hope for upgrades and the like, but I would love the dedicated check in line, elite security line (if offered, I know CO does it for silvers, golds and platinums, but others may only do it for their equivalent of gold and up), and priority boarding (as a college student, I wind up violating the carry-on rules a lot and bring a bookbag and a roller-bag, and usually need bin space for both, so early boarding would be a plus. I also strongly dislike having to argue with people who sat down in my pre-selected window seat and want me to switch to an aisle or middle (selfish, I know, and anal, but I feel airsick in the aisles and middles, but not at the window...). If an upgrade ever got thrown my way of course, that would be nice so any program that gives me an increased chance of those is great. But, like I said, since I tend not to book full fare tickets, I doubt many would come my way.