I love a good action flick as much as anyone. In fact I like them more than most girls my age. However, when you take a story such as "Sherlock Holmes" please do try to stick with the characteristics of Sherlock.
It's a good movie, I recommend it to you, but just keep in mind this is not the Sherlock Holmes you read in High school. I already had it figured out by the time Blackwood "rose" from the dead. In the novels, you had absolutely no idea what the solution would be. In this film, if you have half a brain, you know it by the first half hour.
I still recommend it, just keep in mind all you Sherlock crazies, it's not done in the same fashion as Sir Arthur Conan Doyle would have liked it to be. I would have liked to see more mystery and less brute blood and gut punches.