It is true, financial success in showbiz does not irrevocably translate into great acting, but an actor's empathy with his/her audience proves there's a special connection. It means they are talking the same language, or maybe the public reacts to the chemistry between the artist and the camera.
Sandra Bullock’s acting career is a curiosity. She started out slow, in diverse romantic comedies until she was given her breakthrough opportunity as an accidental bus driver in the successful actioner ‘Speed’, alongside Keanu Reeves. That was a typical “sidekick”/”love interest” role that clicked with audiences and producers alike. Soon after, Bullock was given more and more films, of diverse interest and quality: from her first Golden Globe nomination in 'While You Were Sleeping', to the completely absurd ‘Speed 2:Cruise Control’.
It helps that in real life, Bullock has always kept a low profile, girl-next-door approach to show business. Not your typical “Glamour” girl, she focuses on comedies, not because she is an excellent comedienne (in fact she can't come up with a joke if it's not written for her), but because she has good tempo with comedic material. Only her presence can save films so formulaic as 'Miss Congeniality' or 'The Proposal' (or simply can't, like the bland 'All About Steve') and she is able to push them to their success only based on her personality onscreen.
In 2003 Clint Eastwood offered her the lead in Million Dollar Baby, to which she declined corteously. She was busy with other projects, of course, but the film was so dark and the character so physically demanding, that she might have thought it wasn’t up her alley. The role then went to Hilary Swank and made her a two-time Oscar winner.
This might have triggered something in Bullock and she started doing more “serious” work in films like ‘Crash’ and her Oscar winner role in ‘The Blind Side’, as well as ‘Extremely Loud & Incredibly Close’. Not that she hadn’t done it before with films like ‘The Net’, ‘Murder By Numbers’ and 'A Time to Kill'.
Most of the films I single out in this 10-best list are comedies. I do because one of the things I like the most of a comedy is when the actors are not trying hard to be funny, but they are, and Bullock is able to convey that and more.
She has achieved the status of Star and has become one of the best paid actresses in Hollywood, but more important than this, is the fact that most of the films where she is involved, have actors as her "love interest". This is pretty odd in a male-dominated industry like Hollywood.
Nevertheless, her most impressive achievement as an actress can be seen in a very peculiar film: ‘Gravity’. She was required to hang on wires most of the shooting, and deliver her lines in front of a green screen most of the time, talking to herself and building a backstory that is never shown onscreen. That, by itself is very impressive. When her Character Stands on safe ground at the end of the film, you realize how strong this woman is, and, apart from the precise direction by Alfonso Cuarón, and how Bullock is responsible for most of the feelings you developed during the viewing.