From the Legends continuity it would be, in no particular order:

Palpatine’s endless resurrections.
The sentient, crying mountain on Endor.
The Sun Crusher, the Darksaber (the Hutt battlestation, not the Mandalorian blade) and all of those OP superweapons and Death Star ripoffs.
Luuke Skywalker.
The Crystal Star and Waru
The Jedi Prince series is pretty cringeworthy with all of its ham-fisted environmental plotlines and Palpatine’s three-eyed mutant sons.
Jaxxon
Honorable mention to the Holiday special.

From the new canon it would be the Inquisitor sabers every time they are used to fly.