These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Colbert Bump - Part of the reason he keeps appearing in so many video games and dramas. His appearances in such often results in jumps in ratings, viewer ship, and sales.
Crowning Music of Awesome - Pretty much all of Mars, Rebirth and Crescent, especially "Birdcage, Oasis and Oreinji no Tayoui". Single-only songs include mentions also go to "Cube", "Blue" and "Uncertain Memory".
Although NEVER to replace Ai Wo Torimodose as Fist Of The North Star's iconic song, the song for New is widely recognized by fans as the best song the series' had since.
Fandom Rivalry: Gackt vs. Mana. This one has some very deep roots and enough anger and bitterness to go around for all, to the point where it has resulted in the Bar Brawl, many a Flame War to the point of reaching Internet Backdraft territory, and unlike many other such events and scenarios, both parties still actively hate each other, which puts it beyond the usual Fan Dumb. Gackt fans will see Mana as an egotistical perfectionist who destroyed his band for the sake of a personal feud, and Mana fans will see Gackt as the egotistical band-destroying jerkass who screws over nearly everyone with whom he works at some point and Mana being the only one with enough balls to call him on it and kick him from the band before he left.
Memetic Mutation - A dark version of this. Gackt's decade old joke about being a 496 year old vampire has been quoted out of context for so long that even presumably legitimate news sources have treated this as a serious belief of his. He has since corrected this at the Nemuri Kyoshiro press conference, where he released his actual age to the public so the joke would die.
Also, within the fandom, his love of Hyde, "fiyaa" and his unceasing use of the word dakishimete in nearly every song he has ever written are memes.
''"I need joh fiyaa fiyaa fiyaa to keep me wahm / I gah too fill za fiyaa / Tu keep me wahm, I gah to feel it...fiyaaaaaa!!"
Memetic Sex God - He's been voted Japan's sexiest man, best looking in a suit, best looking in a kimono, best looking in a tuxedo and best looking as a samurai.
Viewer Gender Confusion: Show someone who has never herd of Gackt a picture of Gackt. Odds are they will not figure out their gender