This might not count (although there have been plenty of Terminator comics), but how about John Connor in Terminator 3, Terminator Salvation and Terminator Genysis?
Given that Connor is supposedly such a brilliant leader and all around badass that Skynet has been forced to send multiple killing machines back in TIME to kill him because he's so elusive and lethal in their present, once we finally got to meet adult John Connor, the results were... disappointing, to say the least.
In T3, we're introduced to Emo Drifter John Connor, who spends most of his time moping around, looking afraid and getting his ass kicked. Nick Stahl is a good actor, but he was so wrong for this role it's just sad.
Next up, we got what SHOULD have been the quintessential John Connor. They had the perfect actor in Christian Bale. They had a futuristic, war-torn hellscape setting, breaking away from the typical "send a robot back in time to kill John Connor" plot of all the previous Terminator films. And yet, this version just... sucked, because SURPRISE! This isn't a movie about John Connor at all folks! It's a star vehicle for Sam Worthington, so we spend most of the movie following his a**hole character around and periodically get little vignettes featuring Connor saying obvious things like "If the Terminator kills my mother before my birth, I won't exist." Such a weird thing to do.
And then of course you had Weird Evil Liquid Metal John Connor in the next movie. The less said about that nonsense, the better.