My best hell time is 2'56"1.
My best times on video are 1'46"0 for Last Cave, but that was because I did it with 3 hp (can still get a better time)
(Link)(I might record a better time for this later, if requested).
And for a hell run on video, I have 3'17"6, which is not as impressive as my newest time.
(Link) Also the video's sound is different in the second part since I experimented with 2 different types of sound recording methods for both parts (I now use the latter method).
Doing a hell run is pretty easy now, but there are still some things I cannot do that the ALMIGHTY GREATEST TIME ON VIDEO manages to do.
1) Get my missiles to lvl 3 before getting to the door where you can make the missiles spawn on the otherside of the wall, killing one of the deleets faster.
2) Haven't mastered using lvl 2 missiles to kill the first deleet.
3) Use the booster down the hallway that's only 1 block high, after defeating heavy press.
4) Get through B2 without taking ANY damage (the guy does it, he has incredible luck).
5) Kill Ballos in only one cycle on his third form (guy does it with lvl 3 missiles, have yet to find out how to recreate his technique).
Part of me believes that the video, along with the TRUE flawless last cave 3hp video were Tool Assisted, but I cannot be sure.
[Edit]: DB, I'd say that using anything 3rd party program, heck using anything besides Cavestory, an operating system, and a keyboard, is considered cheating. It should be humanly possible for everyone, without ANY program or modification. The only modification in my 3hp last cave vid is the addition of the nikamaru timer btw.