I think the fact that you do not find him very attractive might play a part in it. It is hard to really explain just why he makes a good Bond, it is just the character and demeanour that he brings to the screen, he looks very suave and serious, calm and collected and with him we can see a person who is a cool and capable killer, at times he is rugged and at times very clean but he always seems believable, at least to me, his comedic side is not the worst either, I felt that in Skyfall his chemistry with Judi Dench as M was very good.
With the decision to drop Pierce Brosnan, Barbara Broccoli was determined to cast a James Bond more in line with the character as Ian Fleming wrote him. This fit in nicely with deciding to produce Casino Royale, the first of Ian Fleming's James Bond books.
If you've ever read one of the James Bond books, you will know that Daniel Craig - who carries with him more of the ruthless killer and Bond's dark side - comes closer to the literary character than any of the previous actors who played 007. (Aside, perhaps, from the blonde hair. I seem to remember the description of Bond as being the tall, dark and handsome type.)
Imo, Casino Royale is one of the best Bond films, in terms of plot, direction and acting. The twists keep coming relentlessly, right to the climax, and Eva Green as Vesper (perhaps the best Bond girl) is the perfect femme fatale to shoot Bond in his Achilles heel of falling for a beautiful woman.
Daniel Craig is a very good actor and his rough and tumble Bond is a believable one. The main drawback of his portrayal is the lack of humor and charm - in short, he's too stiff for his tuxedo.
While Sean Connery was perhaps a bit more gentlemanly than Ian Fleming had written the character, his infusion of humor and charm into 007 - while still maintaining his no-nonsense license-to-kill masculinity - is what really made the franchise. If there hadn't been a squabble between Cubby Broccoli/Harry Saltzman and Connery, the role probably would have been Connery's at least through to the end of the 1970s.
I found Skyfall to be a good Bond film - not better than Casino Royale, despite very good directing by Sam Mendes, but far better than the awful Quantum of Solace.
However, in watching Skyfall, I found the seriousness with which Craig's Bond takes himself had begun to wear thin. For me, three Craig Bonds are enough. Unfortunately, with the considerable attention devoted in Skyfall to Craig's Bond warming up to Ralph Fiennes - who has now assumed M's mantle - it seems we've been softened up for at least one more Craig venture.