Bike shop I was at recently told me Continental tubes were the best ones they sold. They are the Race Light versions. I was concerned about the "light" but the mechanic said they have had no problems with them. I have Vittoria Diamante Pro tires, and so far so good.

Are you sure you are at 120 psi? Maybe your pressure is getting a little too low and causing a pinch flat. I've noticd the pressure goes down a little faster with these Race light tubes vs. my old tubes.