I rewatched Anchorman recently, it hasn't stood up well over the years - at all. Steve Carrell's character actually came across more as undeniably lame, and annoying than actually funny. Which is a shame, since I really used to love that flick. I saw Talladega Nights in theaters - it made me cringe.
Elf still makes me laugh, and I saw a good chunk of Step Brothers once, which completely exceeded my low expectations. I'll have to watch the whole thing eventually.
I personally think Ferrell is at his best when playing secondary characters. Take Mugatu, from Zoolander, for instance. Ferrell completely stole the film. Which is hard to do, considering just how funny, and quotable of a film, Zoolander really is.
He was also hilarious in both Old School, and The Ladies Man, where he played a secondary character in both films. He's incredible at playing off of other actors, but his performance weakens greatly once he's in the spotlight.
I also thought he did a stellar job lending his vocal talents to The Oblongs.