I got the entire Bond film series for Christmas, so I'm watching all of them.
Right now, I'm on A View to Kill. Connery's Bond movies were fantastic, especially Goldfinger and Thunderball. George Lazenby is underrated; On Her Majesty's Secret Service is one of the best films in the series. Roger Moore is alright, his movies range from awesome (especially The Spy Who Loved Me) to meh to "WTF IS THIS???."
I haven't gotten to Timothy Dalton, so I don't have an opinion of him yet.
I grew up with the Pierce Brosnan movies, GoldenEye and Tomorrow Never Dies are two of my favorites in the series, World Is Not Enough is alright, Die Another Day was just ludicrous (but I'm giving another chance this time around).
I never watched any of the Daniel Craig movies except for Skyfall, but I enjoyed the hell out of Skyfall, so I'm looking forward to Casino Royale. I heard Quantum of Solace was terrible, though.