Things Fred and George are besides troublemakers:
they figured out how to use the Marauder’s Map during their first year
they both received good marks in their first few years at Hogwarts
they drove their dad’s flying car without any training
they knew how to pick a lock using Muggle methods
they actually memorized the entire Marauder’s Map by their fifth year
they correctly predicted the outcome of the Quidditch World Cup
they made a successful aging potion so they could put their names in the Goblet of Fire (of course, Dumbledore had the age line which knew they weren’t of age, but their aging potion was a success regardless)
they started a highly successful business from scratch before their sixth year
they invented a great load of things for their business (which takes time, intelligence, and money)
found a way to disguise their products so they could be delivered to Hogwarts students
they passed their Apparition tests “with distinction”
they knew what the Vanishing Cabinet was and shoved Montague in it, knowing he wouldn’t come out for weeks
they turned corridors at Hogwarts into swamps
helped to keep Potterwatch going
tried to send Harry a toilet seat when he was in the hospital wing after fighting Quirrell and Voldemort
tried to keep the rogue bludger away from Harry in his second year
they rescued Harry from his abusive home before his second year at Hogwarts
didn’t take the rumors that Harry was the Heir of Slytherin seriously
both of them were ready to attack Malfoy when he called Hermione a “mudblood”
decided to give the Marauder’s Map to Harry because his “needs are greater than ours”
comforted Harry after the dementor attacks
they allowed Harry free merchandise from Weasley’s Wizard Wheezes because he gave them the thousand galleons to start their shop
defended their brother when the Slytherins came up with “Weasley is our King”
defended Harry when the Slytherins insulted his mother, Lily Potter
started an all-out rebellion against Umbridge for her punishment practices
volunteered to take Polyjuice Potion to disguise themselves as Harry Potter so they could safely transport the real one
constantly defended their family from jokes about wealth, blood status, and appearances
requested that Percy sit with them instead of the other prefects in their third year because it was a “family holiday”
they were very proud of Ron when he beat McGonagall’s life-sized wizard’s chess
tried to cheer up Ginny during her first year, even though she’d been under the influence of Tom Riddle
joined their family in Egypt (even though they tried to lock Percy in a pyramid)
(sort of) comforted Ron when Scabbers went missing in his third year
they bought Ron a brand new set of dress robes under Harry’s instruction
they spent a majority of their Christmas holidays during their seventh year at St. Mungo’s after their father was attacked by Nagini
defended their family from Percy’s ignorance on multiple occasions
both still stayed at the Burrow for the Christmas holidays during Harry’s sixth year