There was a thread a while back from a new dad on wind / Colic, and we too had a windy babba (erm, 'top' and 'bottom' venting, LOL), so for the past 8 weeks we've tried different bottles etc.
We had started with Avent bottles and teats because we bought the steriliser which had free bottles. IMHO they were pretty rubbishy. When you use them you can see air bubbles rushing in through the teat whenever baby breaks the vacuum (ie comes up for air), and the mechanism around the collar with the thicker lipped teat just plain doesn't work nicely / efficiently... IF air manages to enter the bottle through the collar (as it should to re-equalise the pressure), the air bubbles through the milk making it more frothy which I've got to believe ends up as extra wind. (I was careful to back off the collar a bit as over-tightening it compresses the teat base too much, blocking the vented channels).
In NICU / SCBU they used NUK teats with dd. These are excellent, though don't fit those wide-necked Avent / Dr. Browns bottles. NUK teats are good because they have a slit in the rubber at the base with the bottle and this lets in air as needed. They fit medela expressing / narrow-necked bottles, and are also sold with their own bottles. You still get bubbles going into the milk though, but as a cheap / easy solution, they seemed to work. Washing is just teat / collar / bottle.
A week or so ago we bought 4 Dr. Brown's / B-Free bottles (there is a massive palaver re: the name / design licensing for the UK; I believe they are near enough 100% identical regardless of packaging / branding). I think these are the best bottles we've tried. They definitely reduced the air getting into the baby. When the baby pulls away, there is no rush of air in. As the baby takes greater quantities of feed, there is no continual 'bubbling through' of air. They are a PITA to wash (loads of little bits), but you get used to it and can wash them fairly fast after a little practice. They also take a wee bit longer to reassemble. I think it's worth it and will only use these bottles going forward (maybe unless travelling as the NUK teat is not bad and less faff).
The big question though is whether this dramatically changes babba's wind... I think it is hard to tell... there are always so many variables, but the post-feed burps do seem milder / fewer, and the frequency / amount of posseting / sickups seems to also be much reduced, and dd seems better on them - although she is getting older, has bigger / stronger tummy / we're perhaps (hopefully ?) getting better at giving the right quantity of milk, in a position which suits her, and are probably better burpers etc. etc. so it can be hard to isolate the 'cure' IYSWIM)
Over to anyone else: Favourite bottles / teats and why...