I haven't posted any countdowns on this wiki or any others so I'll try with this one.
20: Pokémon Heroes vs Disney and Non-Disney Villains by BrerDaniel/DisneyDaniel93.
19: SuperMetalSonic1985's Villains War Tournament by SuperMetalSonic1985.
18: Free for All Villains Tournament by DryLuigi.
17: Non-Disney Heroes vs Villains by Zachary Baker (old) and Fattus Cattus/Bertie12 and Corey the Keyblade Warrior (new).
16: Free for All Heroes vs Villains Tournament by Rizo2612 Studios.
15: Video Game Villains War by Dagwood525.
14: DC vs Marvel Villains by Injusticelord.
13: Movie Villains War by ZareltheKiller/Sasoricrocodiel.
12: Non-Disney vs DC Villains by Sonihadow21.
11: Worst Villains Tournament Ever/Worst Heroes and Villains Tournament Ever by HCFortan/Miro Floydike/Alffan 1938/Manuel Lobato Humanes.
10: Villains Battles by Saverio Gamba.
9: Disney vs Marvel Villains by GAVillain.
8: Disney Villains War by TheCultofKefka/Mister Dark.
7: Animated vs Video Game Villains by EpicKirby/Dr. Freeman and ToonMaster707.
6: Cartoon Villains War by BaronofShadows1685.
5 Disney vs Anime Villains by EvilSkeletonKing.
4: Non Disney Villains Tournament by Sonihadow21
3: Disney Heroes vs Villains by acemckillayoface
2: Disney vs Non-Disney Villains by Manwhoooo and 73Windman
1: Heroes vs Villains by CKPrimeval07 and Acemckillayoface
Honorable Mentions: Any war by wjacob1000. Transformers vs Disney and Non-Disney Villains by DinoFreakUSA (old) Calmvolt/Electric Drago (New). DC Marvel War of Gods by Injusticelord. Any war by Dr. Animatronic/Adrian Clemonts. War of Anime Villains by Koroko Yasshidesu. TheMadDoctor's Villains War. Villains War, Heroes vs Villains and Anime Villains War by Disney Knight. Disney vs Marvel and DC Villains by Dark Villains. Any other war by Saverio Gamba (includes Cattivi dei Prequel vs Cattivi dei Sequel, Non Disney Villains War, Villains War, Disney/Non/Anime Villains fights and Animated vs CGI Villains War)
The Rest like Animated Heroes vs Villains by Koroko Yasshidesu, and one off's like Gibson family's and Dark Villains, Zachary Baker's Google Photos Tournament, Greatest Heroes vs Villains Tournament by Gabriel Madriz Mora and Manuel's Villains war are Okay
But some I find interesting like War of the Disney Villains Kefka's One off, Battle of the Disney Villains and Live-Action Villains War GA's One offs, Saverio Gamba's one offs, Bertie12's one off's, sometimes Disney villains, Best are Villains and villains war these user's have interesting ones, Calmvolt's one off's (Attack of Godzilla, Disney Villain Fight/Legendary Pokémon Heroes vs Disney Villains, Transformers vs Non-Disney Villains, Non-Disney Villain Fight, and both part's of Maleficent's Forces vs Bill Cipher's Forces) and Rizo's one off Team Mario vs the Forces of Maleficent.
Even some you thought up on this wiki have my interest as well some are good while the others are okay along with some on the forum.
That's all I have to say so I'll be busy on some other wiki's/account's Liam Connolly.