I've always been a fan of the Bond films, which doesn't mean I like all of them (some are truly awful, especially in the later part of the Roger Moore era), but I certainly enjoy quite a few. I have favourites for each Bond, and I struggle to compare them as they are all so different.
Favourite Connery- You Only Live Twice.
I love the far East setting, and it has not only the most iconic villain in Blofeld, but also the volcano lair. One of the classics (though only narrowly beating out Goldfinger)
(I should add that On Her Majesty's Secret Service is also a great Bond film)
Favourite Moore- Spy Who Loved Me
Roger Moore is very hit and miss for me. I didn't take to his brand of corny comedy and silly villains, and some of his movies are amongst the worst in Bond history. This one is probably the most similar to the other Bond films (Jaws aside, and this is a much more menacing Jaws than in Moonraker), and has a decent balance of action and plot.
Favourite Dalton- License to Kill
I love both of these movies, but I always preferred this one. A total reinvention of Bond, and a much needed reboot of the series.
Favourite Brosnan- Goldeneye.
Anyone born in the mid to late 80s is bound to have this near the top- I lived on Goldeneye 64 for many years, and this film will always be amongst my favourites because of that. Tomorrow Never Dies is great for the first three quarters and then ends poorly, with a pathetic villain, while The World is Not Enough is also a great Bond film. Die Another Day is probably the worst Bond film ever made.
Favourite Craig- Casino Royale
This invented the new Bond brand, and so far this is a brand that I have really enjoyed. It has brought a reality and grittyness back to the role that was present in the books, but rarely in the films. Skyfall was also a brilliant film, but Casino Royale, despite weaker perfomances, has more balance as a story.