First off, the cinematography was amazing. But Deakins always shoots beautifully, so that is to be expected. Also, Sam Mendes is BY FAR the best director they've gotten for a Bond film in quite a while. It really was a stunning film to look at.
Ultimately, this is probably the closest I have gotten to liking one of the Daniel Craig Bond films without exception or disclaimer. It felt a bit long at a few moments, but just a bit. I still think the move to a more serious/less campy Bond franchise is, personally, a bit dissatisfying, but this one had a pretty good balance of serious and fun. I'm still not wild about Craig, but that's entirely a matter of taste. I recognize he's a good actor, but I just don't much like him for some reason. But these are all pretty minor things. I generally enjoyed watching the film from start to end.
Most triumphantly, Skyfall is the first of the Craig films that actually felt like a Bond movie, rather than a generic action flick that just happened to have gadgets and recognizable theme music. All the little callbacks to the old films made me very happy and somewhat optimistic about the rest of Craig's tenure.
Oh, also, Javier Bardem was perfectly delightful as the villain.