Geistalt
SilenceThatSpeaksVolumes
1. Probably Dorsk 81's Force Push against 17 Star Destroyers out of the Yavin system, tbfh; either that or Kyp and Luke taking control of those black holes produced by dovin basals (which simply isn't that impressive imho).
2. I haven't the slightest idea about any of UnuThul's feats, so I'm just going to go with Vitiate casually/effortlessly reading the minds of everyone on the strike team dispatched by the Jedi to capture him (followed shortly thereafter by the Dread Masters killing all the forces that belonged to one of the factions that fought against them on Oricon and Kreia and the Exile's mind-reading of the rest of the latter's crew). Then there's Abeloth's ability to mind-slave whoever she wants into serving as one of her thousands of hosts bodies on a whim.
3. If the Starkiller clone did, in fact, use Force Lightning to disintegrate that Nebulon-B escort frigate he was on, then that; if not, Sidious' Force Storm (followed shortly thereafter by Force Maelstrom–and, if that's not accurate enough, his Force Lightning feat from Return of the Jedi). The closest anyone else has ever gotten to that as far as I'm aware is Darth Malgus' Maelstrom, his in-game "Unlimited Power" technique, and/or his simultaneous use of Force Lightning on all 4 members of the Empire's Fury or the Coruscant Aegis. That's just as far as I've seen, tho; Luke probably has stronger Force Lightning than either of them. And then there's that one time Exar Kun fried Naga Sadow's untamed Sith wyrm to death.
4. Yoda deflecting Sidious' Force Lightning.
5. Either Galen Marek using this to protect Rahm Kota and the other Rebel leaders from Darth Sidious' Force Lightning or Satele Shan absorbing Darth Malgus' lightsaber plasma.
6. Mace Windu's Vaapad amp.
7. Darth Krayt using Dark Transfer while in the grave.
8. Probably something Abeloth did.
9. Darth Sidious' concealment of the fact that he was Force-sensitive.
10. Malak's 20-second-long use of Force Stasis against Revan.
11. Remulus Dreypa setting his general premises aflame.
12. Jaina Solo Fel's use of Beast Control on multiple beasts at the Corellian Livestock Exchange and Exhibition in 43 ABY.
13. The Ritual of Nathema.
14. The birth of Anakin Skywalker.
15. Cade Skywalker's use of Force Barrier to ensure he and Deliah Blue'd emerge from the incineration of Darth Maladi's lab unscathed.