This is the new list of the hardest legitimately completed (and rated) level of each year

Data from GD Fan Wiki and Stormfly

2013: Bicycle

- creator: Back

- verifier: Back?

- difficulty: Hard Demon

Most people say it was BP night, but that level is easier than both Bicycle and Demon World. BP night also has a secret way and wasn't legitimately verified.

2014 (unsure): Stereo Demoness

- creator: Majack0

- verifier: Hack by Majack0, legit by Crack

- difficulty: Insane demon

People say it was ICDX but that was hack verified and wasn't legitimately completed until 2015. As for the actual hardest, many top 1's in 2014 were hacked including Stereo Demoness, but there is a chance that the nerfed version which is an insane demon was completed by Crack (the guy from Bloodbath) in 2014.

2015: Bloodbath

- creators: Riot and 10 others

- verifier: Riot

- difficulty: Extreme demon

- There really isn't much to say bc no levels significantly harder than Bloodbath were completed until 2016.

2016: Sonic wave

- creator: Cyclic

- verifier: Hack by Cyclic, Legit by Sunix

- This level's difficulty was unmatched for way too long.

2017: Death Corridor Z

- creator: EternaswipVMAX i think

- verifier: Sunix

- I genuinely thought it was Plasma Pulse Finale but it turns out Death Corridor Z is three spots above rn. I still believe PPF is harder but I'm going of stats rather than actual opinion.

2018: Crimson Planet

- creators: TrueOmega and 10 others

- verifier: Wooshi

- Anyone who says Bloodlust is lagging, because unlike Crimson Planet, Bloodlust is not in the Demonlist.

2019: Kenos

- creators: Bianox and 14 others

- verifier: Npesta

- GUYS IT'S NOT ZODIAC. For a while it was Zodiac but recently it switched with Kenos on the demonlist so Kenos is harder.

2020: Tartarus

- creators: Riot and 9 others

- verifier: Dolphy? (there is a chance that he might have hacked the level, if not him, then Mullsy)

- I hope that kid Fcking dies.

2021: Slaughterhouse

- creator: Icedcave and 6 others

- verifier: Hack by SpaceUK, Legit by Doggie

- At first I thought it was SWI, then Arcturus, then Firework, only to realise Doggie beat Slaughterhouse in late December. If we were considering unrated levels, the hardest level could've been VSC but there's still a debate as to whether that or SH is harder.

2022: Silent Clubstep

- creator: Salient

- verifier: Paqoe

- Acheron got moved below SC recently and SC was verified before Acheron.

2023+2024: Tidal Wave

- creator: Onilink

- Verifier: Zoink

I literally just found out Tidal Wave was verified in 2023 and since it's harder than Avernus that makes it the hardest for more than a year.

2025: TS2🥀

- creators: CairoX, DrCuber and the rest of the world (I swear there were like 30 people in this level)

- verifier: Zoink

- A swing and a miss... wait, a swing and a home run 🔥🔥🗣️.