What is the best carrier for my new Nexus?

In the same boat. I'm looking to free myself from Verizon's chains and venture into the unlocked phone world. Although I'm not looking to get service with T-Mobile since their coverage is terrible around here. AT&T does a lot better. I'm not entirely sure about the prepaid route yet as I get a rather hefty discount for postpaid plans from the company I work at (although prepaid would still be a little bit cheaper).


My company does a discount with AT&T as well (on par with the Unlimited plan on Straight Talk), and coverage is quite good. The beauty is that bringing my own phone would mean it's a "contractless" postpaid plan.
 
Im on AT&T, made a switch back (like 5 months ago) to them after Verizon pissed me the hell off. But im now debating on going to T-Mobile for there unlimited DATA and I will save $40 a month with them for both my lines. Only thing stopping me is i'm scared of there service.
 
I just ordered a $99 galaxy s3 on ATT off amazon. Have a spare S3 already that I am going to use until the nexus 4 arrives. Am going to sell the new s3 and also ditch my g nexus. CANNOT wait.

I decided against t mo since they do not have an LTE network. if after 9 months a new phone comes out that is amazing and has LTE i will be able to switch with ATT, with t mo im stuck on HSPA.