I'm very picky when it comes to who plays who in biographical films. Sometimes the casting is right, other times...
Val Kilmer/Jim Morrison- Looking at them side by side they aren't dead ringers, but Kilmer captured Morrison's energy. That's no small feat. Tons of rock singers have been trying and very few come within striking distance. In Oliver Stone's 1991 film The Doors, Kilmer basically made Morrison less of a prick and that in itself is just great.
Leon/David Ruffin- David Ruffin is one of my favorite singers and boy did he ever get the once-over in that 1998 TV-movie, The Temptations. Portrayed as arrogant, desperate and unlikable, Leon had the task of basically bringing Ruffin back to life. It was good not great. Leon certainly captured Ruffin's anger and general oddness, but not his intelligence. In fact he made Ruffin seem a bit "dumb" and listening to the genuine article or listening to him speak, he was anything but "dim."
Brad Garrett/Jackie Gleason- Although Garrett earned some raves for his 2002 portrayal of Jackie Gleason, I just couldn't buy it. I found the film extremely depressing and just not worth the time. On an odder note, since Garrett is so tall and Gleason wasn't, the sets had to be constructed to make Garrett not seem like Gigantor opposite his normal, life-sized cast mates.
Mark Addy was supposed to play Jackie Gleason in Gleason but had to drop out.
Justine Waddell/Natalie Wood- It's not like I still have a crush on Natalie Wood or anything (yeah right) but this was ridiculous. I can't imagine, really. Wood was a nonpareil entity and for the sake of brevity, Waddell didn't capture anything reminiscent of her. It's not her fault really...
There's the original, it's not close at all.
Joe Mantegna,/Dean Martin. Not quite. Mantegna played Dean Martin in 1998's dreadful HBO film, the Rat Pack. It's was misfires abound, especially Ray Liotta as Frank Sinatra. Mantegna gave him a run for his money. Playing Dean a bit as stolid and oddly doltish, the film ignored the fact that Martin was kind of, well, cool.
Part 2: The best Dean Martin portrayal was probably Tom Hanks on an SNL skit. Hilarious and spot on...