I'm by no means an Austen purist (LOVE my fan-fiction - paid FULL price for one yesterday and am finishing it up tonight!), but I had a hard time getting through the 2005 adaptation, it had it's moments, but it's so hard not to compare it to the 1995 BBC miniseries (despite the 4 hour run-time difference) which was just so true to the book. Oddly though I had a lot less issues with the 1940 Laurence Olivier version, which borders on the silly at times!
Totally off-track, but if you need a laugh YouTube "Mr. Darcy I'm too sexy" - there's a version for both 1995 + 2005 adaptations.