We have only ever used Phillips Avent Classic Bottles. Got some free ones as samples when we set up our registry, and they seem to work great! DD usually BF but they work for the times when we're apart and she has to take a bottle.
My Dr Browns bottles have been leaking too! I thought it was just me. We got some new, bigger ones and haven't had an issue. If you don't want to buy new bottles, or want to keep using using Dr Brown's brand, here's some tips: 1. Size up. Our 4oz bottles started leaking once we reached the 4oz level. We now use the 8oz size, even though the baby is not drinking that much. 2. Make sure there's nothing on the rim of the bottle to prevent a good seal. For us, that means making sure there's no formula powder or water on the rim before we put the white seal thing in the bottle. 3. Don't shake the bottle. 4. Don't heat the bottle with the cap on. If you can, heat the milk in a different container, let it cool a little bit, then pour it into the Dr brown's bottle. The pressure from the heat can prevent a good seal, and it forces the milk up the air tube and causes leaks. These tips have helped us. I hope they can help you