Personally, the best vibes I have tried are Lelos - particularly Isla. But they are highly priced. Once ya try one though, you'll see why they can ask for that price.
If you want a cheaper vibe that still is great, I recommend Evolved - Bendable Touch for a rabbit or Silicone Seduction which has some give in the shaft.
A lot comes down to price and size. Plus, do you require something that is quiet if you live with others?