Occurs to me on reflection is that what Ritchie has done, probably unintentionally, is to resurrect the notion of "high camp"-- that kind of cliched, over the top and even kitsch-y stuff that typifies say, Busby Berkley musicals.
It is often great entertainment and such is the case with "Sherlock Holmes"--as long as you accept that it's all balderdash.
All the actors in the movie are great and memorable and I think Robert Downey Jr. and Jude Law are as effective a buddy duo as Paul Newman and Robert Redford...
The evil Lord Blackwood, played by Mark Strong, is fantastic.
This movie is of course NOT Arthur Conan Doyle. It IS however a send up ( as I have written elsewhere) of every buddy film, detective story and action movie every made.
Loved Holmes final confrontation with Blackwood high above the Thames ( on the scaffolding of what is to become the Tower Bridge?)-- where Holmes explains how all of Blackwood's "black magic" has been achieved ( shades of Charlie Chan and "The Thin Man'!").
Fantastic escapist adventure. Violent fights are well staged --one is almost a quote from "Raiders of the Lost Ark" with Holmes facing a tough giant of an opponent ( with a different ending, however).
Also loves how Holmes is always getting kicked around (as also happens to Watson) in the pursuit of the triumph of Good over Evil.