When You Buy...Do you buy Retail, Contract, other?

So I am curious, When I bought my Galaxy Nexus on Verizon I paid retail for the phone. I ultimately decided that I will never sign another contract with Verizon ever again, as 1) I like my unlimited data and 2) It is actually cheaper in the long run.

So how do you guys do it? Do you buy your phones retail? Or do you just upgrade using the tradition subsidy/contract option?