How to explain this? Okay, so take all your character journals and list 'em. Then explain why you picked that LJ name for them/story behind the LJ name/etc. etc.
Tommy Oliver,
whtrngrtgrpwr: Tommy's personal theme song while he was the White Ranger was White Ranger Tiger Power.
Jack O'Neill,
gategolfing: During the episode of Stargate SG-1 titled "Window of Opportunity" Jack, while stuck in a time loop, hit golfballs through the Stargate.
Wallace Sullivan,
fateschosen: The Golden Digimental he received was the Digimental of Fate.
Felix Renton,
l33tchair: He's an avid gamer for one, plus his chair is actually tricked out enough to be dubbed l33t.
Impmon,
demonredeemed: Once an awful, immature Child Digimon, then a violent Demon Lord Digimon who didn't care who he destroyed, Impmon realized the path that he had been going down would only lead to more misery, and decided to return to his Tamers and become one of the Digimon that helped stop the D-Reaper.
EDIT
Might as well add my reserves:
Leanbow,
lupine_flame: He calls himself the Wolf Warrior, and his magical element is fire.
Taichi Yagami,
couragegoggles: Pretty much self-explanatory.