In the comic books, he's been portrayed over the years as a psycho, a hero, and a tragic figure. He's gone from silly to serious, and there were some great moments in his character's history. In the movies, it's been a toss-up as well. In Batman Forever, Tommy Lee Jones portrayed the character as a weird variation of the Joker. He had this weird purple face that was hard to take seriously, but in all honesty it was the least of the worries for the franchise at that point.
In the comics he is one huge, bald-headed white guy. In the Daredevil movie, he was one huge, bald-headed black guy. In the comic books it was hard to imagine him being fast enough to be a serious threat (especially if you've ever had to walk behind a fat guy in the mall). In the movie, we saw enough muscle in there to see what he was capable of.
The Daredevil movie wasn't that great, and I'm honestly not out there pushing for a sequel (a reboot, yes) but I wasn't really impressed with either villain in that film...or even the hero for that matter. Could have been worse though, I suppose.
This character was radically different in many ways. In the Iron Man movie, he was old and worked for Tony Stark. In the comics he wasn't that old and had his own rival company taking on Stark Industries. Still, you have to admit the final armor in the movie was a nice challenge for Iron Man. He was one big dude.
The comic book version of this villain has been a pest, a private eye, and now a psycho again. He's a complex villain who may make some deep statements but always keeps himself presentable.
Jim Carrey, on the other hand, took the guy up about 18 notches and turned him into a really funny villain you had trouble seeing as a serious threat. He made the TV version of Riddler seem calm! To Jim's credit, however, he was the first Batman villain to actually make it through one of his movies alive. Unfortunately (or fortunately, I guess) we'll never see him in a sequel. I still think Michael Emerson would make a great Riddler for the next Batman movie.
Ra's Al Ghul
This one is hard to score. The comic book version is a tough guy with a lot of issues. He has a daughter madly in love with Batman (and even had his son). The movie version was the guy from "Taken", which remains one of my favorite movies of all time.
While I wasn't overly impressed with Liam's overall take of the character, it did make for a rather nice plot twist in the "Batman Begins" movie. I liked how he was Bruce's mentor before becoming his enemy.
This one was actually pretty good. Despite having a lot of leeway in this, they stayed fairly close to the character. The costume was exact, but they were close enough to see where it was coming from. Cillian Murphy did a good job of having that "trust me" look that turned into a "HA! GOTCHA!" moment later.
I wish he'd gotten more of the costume besides just the hood though. It sort of made him look like he'd done his costume shopping at the Thrift Store.
Lots to complain about here and lots to love. On the one hand, they took this rather cool character from the comics and turned her into this weird freak for the movie. I can understand the need to make her seem more motivated to hate people, but it could have been done differently.
On the other hand, there was no need for her to have to constantly change clothes when she changed identities in the movie. That was an interesting touch, though it could have been overlooked or explained with a costume, I guess.
Another one that kept the essence of the character while changing the overall look (and origin), this one made for a pretty cool fight in the second X-Men movie. While the outcome was never in doubt, you have to admit it was kind of touch and go there for a while.
Personally, this is one time I'm glad they didn't go with the comic book costume. To me, it would have been a bad choice and almost impossible to pull off. It would have made the character seem far too comic book and not threatening. The way she was set up, the Wolverine fight in the end was two sleek adamantium warriors going at it.
While this isn't a movie character, I wanted to give him a mention. When we heard that Doomsday was coming to "Smallville", we knew it was going to be a hard thing for them to do. For one, we knew he wouldn't kill Clark like he did in the comic books, so the overall threat was gone. Second, we knew Lex was gone, so his origin would be in question.
As far as appearance goes, they did their best to stay faithful to the comic character while still making it work for the series. I wasn't that impressed with the human turning into Doomsday rather than him being created as a monster from scratch, but in the end it made for a pretty cool episode.