Throwing out some levels I've played lately off the top of my head:
2-7X is Naija
For Hell you can pretty much slap Naija on everything. 4-14X is Runman, 4-19 and 4-19X are stupid levels where you wait for a platform to descend and do one drop so I have no idea what's best there. Can't recall any other exceptions right now. And how is that video proof for Viridian on 4-3 and 4-3X? That's not even close to Naija's times.
edit - oh yeah, 4-12 and 4-12X are Meat Boy I think? Might be something else I'm forgetting.
5-5X is Naija
5-6 is Naija, see Zed's video
5-7 is Naija, IIRC Runman makes it to the last saws one cycle later, losing by a second or so, not 100% sure on this one
5-7X is Naija
5-9 is Runman
5-9X is Runman
5-11X is Naija/Kid, Naija currently leading (7.45s vs 7.58s)
5-13 is Naija, not close
At the moment I've only uploaded a compilation video of my Hell runs, but I think like one or two of those times are actually the best ones anymore. I was planning to do a Rapture compilation and a chapters 1-3 compilation when I've worked on some more levels.