And the Fandom Rejoiced: Because, if you think about it, it is a freaking miracle that the reunion tour ever even happened. Add to this the periodic fan club cruises and the recently announced "Insane Boy Band Crossover Concert" and you have a very happy fanbase.
Epic Riff: Five "oh"s, to two different rhythms[1], are two of the most iconic vocal riffs in pop music.
Face of the Band: As noted in that trope page, Boy Bands tend to avert this. That being said, Donnie tends to be the most out-in-front in terms of on-stage banter and crowd interaction.
Growing the Beard: The group's evolution from their debut through Step By Step (coupled with some literal beard-growing), as well as their more modern sound on The Block.
Harsher in Hindsight: Jon leaving the group was the final straw that led to their breakup. Years later, Jon revealed on Oprah that he suffered from panic attacks pretty much the entire time he was in the group, and that by the time he quit, they had increased in severity and frequency to the point that he could barely function in everyday life, much less on stage. Jordan was in the same episode with Jon, and revealed that he also suffers panic attacks, but to a much lesser extent.
Hilarious in Hindsight: On the other hand... When the press said that Jon was dating Tiffany, the fangirls screeched. Several years later Jon and Tiffany said yet again that they only were friends... but why is this different, huh? Because Tiffany added "I and Jon never dated... because Jon is Invisible to Gaydar, you know". Guess the fangirls were screwed either way, huh.
"Dirty Dawg." Joey noted that their rapper friends refused to speak to them for a while after that one.
Replacement Scrappy: Joey when he first joined NKOTB, as he replaced a kid who was already good friends with the rest of the guys prior to the group's forming.