Trunks' biggest moment out of his child/teenage years is obviously his introduction of him sweeping in to kick the shit out of Mecha-Frieza. That big buildup to Frieza's return, ultimately him being bodied by this completely new character (who we learn later is Vegeta/Bulma's kid.). I remember first watching his introduction as a child and going, "This character is fucking amazing!" ...then, as the Android/Cell saga went on, he just seemed to be yet another DBZ character in Goku's entourage that was just 'there.' Nothing he's done since killing Frieza seems worth mentioning.
Then Buu Saga came around, and yes while the friendship with Goten's humorous, and Gotenks at the time was cool, it was still a whole lot of boring undeveloped shit, coming from Trunks when looking back now.
What do you think?