Watchmojo, a western company which is a video content creator, with a large following in youtube, recently made a Top 20 Anime Openings of All Time video. Below are the results:
Honorable Mentions:
Kiseki no Umi (Record of Lodoss War, 1998)
Ah Yeah!! (Haikyu!!, 2014)
Voracity (Overlord, 2015)
Inferno (Fire Force, 2019)
Kaen (Dororo, 2019)
Howling (The Seven Deadly Sins, 2014)
20. Hacking to the Gate (Steins;Gate, 2011)
19. unravel (Tokyo Ghoul, 2014)
18. Asterisk (Bleach, 2004)
17. Period (Fullmetal Alchemist: Brotherhood, 2009)
16. THE DAY (My Hero Academia, 2016)
15. History Maker (Yuri on Ice, 2016)
14. Renai Circulation (Bakemonogatari, 2009)
13. Pegasus Fantasy (Saint Seiya, 1986)
12. 99 (Mob Psycho 100, 2016)
11. Ai o Torimodose!! (Fist of the North Star, 1984)
10. The Hero!! (One Punch Man, 2015)
9. We Are! (One Piece, 1999)
8. Colors (Code Geass, 2006)
7. Tank! (Cowboy Bebop, 1998)
6. Guren No Yumiya (Attack on Titan, 2013)
5. Duvet (Serial Experiments Lain, 1998)
4. Haruka Kanata (Naruto, 2002)
3. JoJo (Sono Chi no Sadame) (JoJo's Bizarre Adventure, 2012)
2. Cha-La Head-Cha-La (Dragon Ball Z, 1989)
1. A Cruel Angel's Thesis (Neon Genesis Evangelion, 1995)