I agree completely if you're comparing SNES against any other system up to that point. But it's kind of ridiculous to say SNES's 20th best game stacks up well next to Ocarina of Time, Silent Hill 2, MGS3, Arkham City, Jet Set Radio, etc., etc., etc.
SNES has a crazy-strong library no question, but let's not let nostalgia overwhelm you completely.
You made some good points. I should clarify. The SNES' 11-20th best games rank extremely well against any other system's top 10 up to the mid '90s.
However, I still feel their top 11-20th best games still stack up (relatively) well against any other system's top 10, especially if we're looking at it as comparing another system's #1 to the SNES' 11th best, #2 to #12 and so on until we get to #10 and #20.
For argument's sake, and it's super subjective, but here are 30 quality SNES games in no order
1. The Legend of Zelda: A Link to the Past
2. Super Metroid
3. EarthBound
4. Super Mario All-Stars
5. Terranigma
6. Chrono Trigger
7. Final Fantasy III
8. Super Mario World
9. Yoshi’s Island
10. Super Mario Kart
11. Super Mario RPG
12. Contra III: The Alien Wars
13. Mega Man X
14. Lufia II: Rise of the Sinistrals
15. Seiken Densetsu 3
16. Super Castlevania IV
17. Super Street Fighter 2 (or Turbo)
18. TMNT IV: Turtles in Time
19. Final Fantasy II
20. Donkey Kong Country 2
21. Kirby SuperStar
22. Super Ghouls 'N Ghosts
23. Zombies Ate My Neighbors
24. Legend of the Mystical Ninja
25. Secret of Mana
26. ActRaiser
27. Tetris Attack
28. International SuperStar Soccer Deluxe
29. Any Super Bomberman title
30. NBA Jam TE
Note: Some might sub out some of those choices for PilotWings, Sunset Riders, Axelay, Space MegaForce or any other insane variety of games.
Mega Man X is one of the best action games ever made IMHO, and it's arguable that it's not even in the top 10 SNES games but rather somewhere in that 11-15 range. I would confidently stack up Mega Man X against other system's top 10 games. Sure it's a little light on difficulty but the way the game flows and how little it holds your hand... very few games since have been able to match its sheer brilliance.