Before I do anything else, let me clear something up. This is the story of the fictional detective of Victorian London who solved crimes through his ability to extrapolate complex solutions from relatively small and innocuous clues. This is not the story of a famous porn star in the 1970s. If it were, the title would be John Holmes, not Sherlock Holmes. This means the movie will be filled with scenes of of stodgy white guys solving crimes while eating fish and chips, not some woman having semen shot into her face. Glad I was able to clear that up for you. Moving on.
I titled this Michael Bay's Sherlock Holmes but it's not on the level of Transformers 2. In fact, it's pretty good until it starts copying Die Hard. I suppose this shouldn't be surprising from a screenplay that credits five writers, one of whom wrote Invictus and another of whom wrote XXX:State of the Union and Jumper. Add to this mix director Guy Ritchie, a man who always strives to make quircky, unusual and high quality action films. I say "strives" because he almost always utterly fails, at least in the "high quality" part. I will say that this is his best work so far, a fact I will credit to the fact he no longer has to listen to ex-wife Madonna taking on three guys and a farm animal in the next room while he's trying to edit his movies.
Robert Downey Jr.s portrayal of the famous detective is not 100% accurate but it's pretty good and at least stands apart, in a good way, from every other fellow who's ever played Holmes. I can say the same about Jude Law's Dr. Watson, a character almost always played as an awkward, overweight bumbler when in fact he was a former Marine, a crack shot and was capable of observation and deduction in criminal cases, though not on Holmes' level. The cast is rounded out by the always likable Rachel McAdams as Irene Adler, possibly the only woman Holmes ever loved. While she wasn't the master criminal in the stories that she is in this movie, she did once outwit Holmes, a fact that only caused him to admire and fixate upon her for years after that. The weakest part of the cast is the villain Lord Blackwood, played by Guy Ritchie regular Mark Strong. The character is simply too dull and one dimensional to be interesting, odd since he's supposedly a powerful sorcerer who somehow manages to come back from the dead.
The movie's plot centers around Holmes' attempts to foil the plans of the evil Lord Blackwood, a fellow whom Holmes and Watson captured after he had subjected five girls to human sacrifice in order to gain the power of black magic. It must have worked since Blackwood was hanged but that didn't stop him from walking out of his own tomb. In the meantime, Holmes' former lover Irene Adler, an American criminal (thus mercifully sparing Rachel McAdams the necessity of attempting a British accent), shows up wanting to hire Holmes to find a man who turns out to be one of Blackwood's employees. Holmes is especially interested in who hired her and discovers that he is a professor. If you are at all familiar with Sherlock Holmes lore, I don't have to tell you any more except that we'll see way more of this guy when Sherlock Holmes 2 comes out.
The movie then moves between having Holmes find obscure clues that everyone else pretty much trips over and participating in Bruckheimer-like action sequences that really don't belong in a film about Sherlock Holmes. The movie's okay when not doing one of those or having really dumb scenes like Lord Blackwood convincing some members of Parliament to help him betray their country, society and god by murdering the rest of Parliament so Blackwood can take over.
Anyway, is it worth watching? Yeah, I guess. I'm not sure if Guy Ritchie would appreciate that opinion, especially since I said it was his best work and my highest opinion of it is, "Yeah, I guess." The parts where Holmes is using his brain and interacting with Watson and Irene Adler are pretty good. The parts that rip off Die Hard, especially the final confrontation with Blackwood, aren't. Still, it's okay and people seemed to be entertained. You can't really ask much more of a big budget studio event film. Unless it's Avatar, the big budget studio event film you should see instead of Sherlock Holmes.