Virgin Mobile, T-Mobile or AT&T (Service) + What Phone?

Short phone history, I started with Sprint but had problems getting calls to and from my house, switched to Verizon, which was generally great, but did a family plan and was left footing the bill (which I paid, but they wanted me to make a deposit), so I switched to Boost Mobile.

Eventually I went to Virgin Mobile. I had a much nicer phone with Boost Mobile, but was very dissatisfied with the service (and their web services offer at the time was a blatant lie).

I pay $30-33 a month including tax with Virgin Mobile and I use a LG Flare. Their customer service is slightly worse than Boost Mobile's and the web barely works.

I am a student on a limited income; right now with my part-time job (Winn-Dixie) I get 17% off AT&T monthly plans and no activation fees (I think this is standard practice with no customers). I am in the process of getting back my job with the Medical College here, so technically I would also qualify for any potential discounts for Florida State employees through a technicality.

So there are a few things, which company offers superior service/price: T-Mobile, Virgin Mobile or Boost Mobile? Most plans cost $30-60 a month.

Is going with AT&T worth it? As I have learned you make a down payment on a phone and then pay $15/month until the phone is paid off. Seems pretty insane to pay $400-500 for a phone..but being able to stream videos is nice and then paying $80-110 a month on top of that. I do get 17% off, so the bill would not be as bad as some others get. I was told by an AT&T rep that the maximum discount is 22% off (for Burger King employees).

This phone/plan would be for personal use.

Remaining question would be which phones to consider.

Virgin Mobile: LG Optimus V or Motorola Triumph

T-Mobile: No idea, I have some variation of an Android Galaxy

AT&T: iphone 3, iphone 4, Google Phone, Android, no idea