The League of Extraordinarily Mercurial Gentlemen Who Were Impish Scamps in Their Early Appearances But Became Detached, Brooding, and Dour Later On

1. Charlie Brown, who in the early years of Peanuts was a little wiseacre running around playing pranks on Patty and had a tagline, "I still get my laughs!" that causes me to crack up whenever I read it.
2. Angel, who was a smirking mystery dude who oozed charm all over the first episodes of Buffy the Vampire Slayer before becoming tortured and brooding later on.
3. Gil Grissom, who in the first two episodes of CSI flirted with three women, cracked bad jokes, and played to the crowd when tossing dummies off the roof of a casino while investigating a murder -- a far cry from the later presentation of the character, whose response to Sara's advances is generally a blank stare.

Any I missed?