In all of the Star Treks I've always enjoyed watching the doctors. The characters can't survive without doctor. They all play curcial roles, and I like them.
McCoy - he's such a smartass. And that was the overly dramatic Star Trek so everything was such a big deal then.
B. Crusher - I liked her because she was gentle. Everyone liked her and she wasn't just a doctor. They sent her on away team like actual missions. One time she went with Worf and Picard on a mission and I was like whoa, but she's the doctor. But she held her own. She's awesome.
Bashir - I've just started to watch DS9, but I like what I've seen of this Dr. he's not annoying and he was pretty funny, not intentionally in the holodeck episode when the crew was trapped in the holodeck. The secret agent ep.