Ah, finally a boycott that I can join. (Usually I am already boycotting whatever company is deserving a boycott). I go to a ConocoPhillips station every morning. They have the nicest, biggest stations, and the best coffee too. However, I don't mind going to 7-11, and starting now I will.
Just remember you may be boycotting someone out of a job.
Well, many, but not all, of them sell CitGo gas. Citgo is owned by Venezuela and thus by Hugo Chavez. You might want to try a nice Chevron, BP, Mobil, Shell, or Exxon station. :)