The only other adaptation I've seen is the 1983 miniseries with Zelah Clark and Timothy Dalton, which scared me half to death. But that was probably just because I was around 13-14 years old at the time.
Anyway, my point is that I really don't have any other versions to compare the 2011 movie to so I can't say whether or not it's the best adaptation of the book ever.
That being said, this movie has definitely earned a spot in my Top Ten Best Movies of All Time list. It's heart-trending, witty, intense and joyful, all at the same time. My favourite aspect would have to be the script, which is pure poetry.
The acting is inspired, especially from the two leads, but also Dame Judy Dench's rendition of Mrs Fairfax and Jame Bell's St. John Rivers. The chemistry between the two leads is positively electric, the scenes well-measured and drawn-out, while still retaining much of the original feel of the book.
The only complaint I have concerns the short amount of time given to Jane's early years, which seems to rely on the fact that viewers have already read the book. I understand it's because of time restraints, but it just seems kind of rushed to me. Although, I greatly admire Freya Parks in her very short stint as Helen Burns.
I give this movie 9/10.