While far from my favorite in the game, I did like Gohan. Like his character in Dragon Ball Super, Gohan is far from the best fighter around.
Such as being almost killed by Android 21's mindless clones. You're better than that, Son Gohan!
But his father Goku, and his semi-adopted dad Piccolo find him before it's too late.
He isn't a huge part of the story, but he does lends his powers to crush Android 21, once and for all.
As a fighting character though he could better. Both in the story and online, I did poorly with him. I don't like that most of his ki attacks aren't really ki moves.
You can also play the incarnation of Gohan when he was kid and became a SSJ2. I liked him better as a fighter than regular Gohan.