First I'll list which adaptations I've seen, and then I'll share what I think of particular characters in the different thingies.
1995 TV series -- BBC -- my favorite overall
2005 film -- I came away disliking it
2010 stage production at the Oregon Shakespeare Festival -- I loved it!!!
Lost in Austen 2008 film -- a young woman from modern times gets transported into Austen's novel -- interesting take on things
BBC 1995 -- My favorite portrayal of Elizabeth is right here. She is awesome.
2005 film -- Not quite how I envisioned her, and at times she reminded me a little too much of Elizabeth Swan from another of Keira Knightly's roles.
Stage production -- Awesome. Not quite the same as the BBC version, but I didn't have any complaints.
Lost in Austen -- Of course we don't see Elizabeth very much in this one. What we do see of her was...surprising. But the whole movie was surprising with interesting twists thrown in all over the place.
BBC 1995 -- This is what most closely fits my idea of him, although I envision him as slightly less severe.
2005 film -- No. No. No.
Stage production -- Pretty good. I especially liked how he was so adorably awkward with Elizabeth at the end. That wasn't how I had read it at all, but it worked for me.
Lost in Austen -- No. No. No.
Lady Catherine de Bourgh
BBC 1995 -- Perfect.
2005 film -- Perfect. She's the one character in this film who matched up with my idea of what the character is like.
Stage production -- I don't remember...and of course I can't exactly go back and re-watch it. *sigh*
Lost in Austen -- Again, I don't remember my opinion of her.
BBC 1995 -- Almost perfect. Maybe perfect.
2005 film -- Not sure...I can't remember her that well.
Stage production -- A little over the top, but pretty darn good.
Lost in Austen -- Did we see much of her...?
BBC 1995 -- Not at all how I envision her. I mean, yes, she's a book nerd and likes to show of her (poor) musicianship skills...but it's not quite right.
2005 film -- I don't remember...
Stage production -- I think she's the character I remember the best from the stage production, and she was pretty much perfect. She was usually too busy reading or making music to speak up, but she wasn't shy about putting her opinions out there. Certain members of the Bennet family kept taking books away from her, and others (mainly Jane and Lizzy, I think) kept giving her her books back.
Lost in Austen -- Don't remember...
BBC 1995 -- My only complaint is to point out that Jane is supposed to be more beautiful than Lizzy, and that Lizzy is by far the prettiest of the sisters in this production.
2005 film -- ...? Can't remember it that well.
Stage production -- I don't remember particularly, but I liked her.
Lost in Austen -- No. She seems a little too fragile.
I don't really like how he's portrayed in any of the productions, actually.
BBC 1995 -- I'm not overfond of their portrayal of him, actually.
2005 film -- Can't remember how he's done in this...
Stage production -- *sigh* Again, can't remember...
Lost in Austen -- No.
BBC 1995 -- Good. Perfect, I think.
2005 film -- No. No. No.
Stage production -- I don't remember him particularly, but I liked how they did him.
Lost in Austen -- Not exactly how I envision him, but pretty good.
BBC 1995 -- Pretty darn good. I like what they did.
2005 film -- Didn't quite fit with how I envisioned her.
Stage production -- Awesomeness. Yes, awesomeness.
Lost in Austen -- No. No. She seems a little too smart in this movie.
BBC 1995 -- The character is right, but...but...it just seems like they needed a different actress. Or maybe it was the hair style and clothing that didn't quite seem to fit.
2005 film -- Don't remember...
Stage production -- Don't remember...
Lost in Austen -- Petite, beautiful, great voice, and nasty. Almost perfect. Up until the line "Your secret is also my secret..." You'll have to see the movie to know what I mean. It's a twist that Austen definitely would NOT have written in. lol But which is quite entertaining.