Sad I missed this, because I do really like this movie, but 1) I only have a copy of the Theatrical Cut, and 2) I had waaay too much homework this weekend to deal with.
Anyway, to those who were left feeling very 
by the movie, I feel your pain. Itâs just one of those movies that doesnât make much sense the first time around. Iâve run into three very good alternate readings of the film, and if you watch a second time with an eye out for any or all of those readings, the film makes a lot more sense.
The reading I go with is the one deathbytray described, that in the moment before Donnieâs death, he comes to terms with all his fears about dying alone by getting a chance to live a life full of meaningful connections with other people, which makes the step over the precipice into the unknown, death, not so bad.
The other reading is the straight-up sci-fi reading. Salon.comhas an absolutely excellent Cliffâs Notes explanation of this reading, taking elements from various DVD commentaries, websites, cuts of the film, interviews, etc., and distilling it down into a Donnie Darko Theory of Everything. It even explains the jet engine. If itâs any consolation, there is no way anybody could actually figure out what was up with the jet engine from the movie alone.
I guess if I were really honest, I think I end up mixing the sci-fi and the life-flashing-before-eyes readingsâI think Donnie actually did live that slipstream life in the few instants before he died, so it doesnât matter that it was mostly negated for everyone else; Donnie learned and got what he needed from it, which allowed him to face his demise with laughter instead of fear.
The Salon.com article also mentions a third, very realistic reading of the film, and thatâs simply that Donnie really is paranoid schizophrenic, and weâre watching the story from inside Donnieâs schizophrenic delusions. I think itâs a legitimate reading but not nearly as interesting as the other two.
Also, I love the commentary track with all the actors (theyâre missing Jake Gyllenhal, though). Mary McDonnell is especially funnyâshe seems to have the same problem that I do of âgettingâ jokes about five minutes after the fact, which endears her to me even more.