Need help with upcoming interview: List standout 2d level design

 I have a upcoming interview for a World Builder position for a upcoming 2D MMO.

I'm collecting and burning through as much content as I can, to get ready for the interview. What games(I'm looking for 2D games) have you played where the level design really stood out. While games like Super Meat Boy are great 2D games, being that this is a casual MMO, I'm looking more along the lines of Maple Story or Neosaurs and not pixel perfect platformers (if something really stood out in this genre though, please list it)

Please post any game where the level design stood out to you, it could be from visuals, technical or both.

Super Metroid, maybe? You should probably explain what type of 2D, since there's more than one.

When listing standout 2D design, Mega Man and the like come to mind. However, that would into the pixel-perfect category. 
 
Personally, I think the original Donkey Kong Country trilogy (and the new Returns, as well) were and are the epitome of 2D level design. 

Critically underrated, but I fucking loved Muramasa.

I don't care what anyone says, the original Sonic games had fucking great level design. Particularly CD, that shit was complex as hell in later levels.

Good stuff, keep it coming

Knytt, VVVVVV. Do you own research!

Castlevania SOTN, Limbo, Braid, Super Mario Bros. 3, Kirby's Epic Yarn

Maple story is a great place to start.

Honestly, I think the problem with these 2D MMO's like Maple Story is the fact that they have pixel- imperfect platforming.  The main reason I burn out on these games is because it's such a PITA to get around the environment.  Ledges are poorly distributed and spaced so there's a lot of missed jumps and aimlessly running around.  The 2D sections of Legend of the Mystical Ninja for SNES come to mind as good action/platformery stuff.

dont start naming off other games. they want to know you can think and problem solve, talk about things you like, problems you've run into and show you are interested.  
any fool can google up examples, they won't be interested in hearing that.  
 
relax, don't think too much about what you think they want to hear.  hate to say this but "be yourself." that cliche is true. 
 
good luck.

As if there could be standout level design in a casual 2D MMO.

" Critically underrated, but I fucking loved Muramasa. "

" I don't care what anyone says, the original Sonic games had fucking great level design. Particularly CD, that shit was complex as hell in later levels. "

Does Donkey Kong Country Returns count? Cause that has an amazing level design.