I use Dr. Browns and love them! I've tried a few other brands and the difference is amazing! You can tell that baby isn't getting all that air in her tummy because of the way the Dr. Browns are designed.
They take a few more minutes to clean, but they are well worth it.
We also use mylicon drops in her bottles every day to help cut down on the gas. I think that's been a big help, too! Buy the generic ones ($3.50 vs. $12.00) since they work just the same. Plus, I keep threatening hubby that I'm going to slip some in his drink at dinner... ha!!! Keeps him on his toes... and his stinkiness confined to the bathroom or outside.