Looking for fast paced 2D platformers...

I am looking for some fast paced 2D platformer games to play. It doesn't matter what system. I want to play games that are similar to Super Mario World. I have been playing alot of Super Meat Boy on xbox360 and it is amazing. I really want to find more games like it. The main parts of these games that I like are being able to have a run button and controlling the height of my jumps by holding down the button longer. I'm not a huge fan of beat em up games or side scrolling shooters. I want games that require precision jumps and have very smooth controls. I just recently played Rocket Knight Adventures for Genesis and it is pretty fun but still not exactly what I am looking for. If anyone has any suggestions I would love to hear them. Thank you.