I started off with Avent bottles but I feel that the air valve (the one they say will help prevent colic) is not as good as Nuk, which I am now using. After I switch to Nuk my daughter had no problems with colic.
Of course the best brand on the market is Dr Brown's, but it can be quite costly. So I guess Nuk is alright for the price and quality.
For a 150ml bottle it costs about $15 I think. Also they have the plastic and glass bottles.