I don't really like chihuahuas. My brother in law has one, and it's basically just a useless little dog that makes a lot of noise. I realize one is not indicative of the breed, but it doesn't really play or do anything you expect of a dog. Plus I don't think they're cute.
Other than that, I pretty much like all medium and large breed dogs a lot. And cats too. I had a lot of pets growing up, so I've pretty much experienced the whole range and haven't had any kinds of animals that I truly didn't like. Small dogs are a mixed bag for me - none that I really dislike (except chihuahuas, see above), but they don't really do much for me. Yorkies are probably the exception just because they might be the cutest dogs on the planet and tend to have great personalities.
As far as larger breeds that others are scared of, that's fine. I mean, for the most part, a dog is only as good as its owner anyway - but if you don't know the owner, the fear isn't really irrational. I'll hesitate around pits, especially if there are children around, just because they are very protective of children - possibly at your expense, but for the most part they're very sweet dogs. I love german shepherds, rotties, dobermans, etc.