Well, before giving suggestions, I tried to think of something that would fit the Loonie Duo's style. I mean, they're the mads for this thing, right? ^_^ I figured it ought to be something wacky.
Regarding the choices: (in no particular order)
The Ryu/Sakura lemon: I agree, it's a good short. It's too short for this episode, though. I kind of like Wanderer's idea to put that before a continuation of Warrior's Legacy. ^_^
The LBG/MK crossover: This one really has potential. I could picture the Loons picking this on the Shao Kahn secret alone. ^_~
The N'Sync/Vamps thing: Truth to tell, I haven't read this yet. The mere title scares the heck out of me. -_-;
The Continuations: Of the three, I think NightCreeper's part 3 sounds the most plausible. I can already picture the break scene:
"We found this short tape lying around."
"It is sure you'll be quite pleased with this one."
"Part 3 of NightCreeper's Rival Schools lemon."
"NOOOOOOOOO!"
"He he he! This villain thing is *so* cool!... whoops, mike's still on."
The Tekken thing is silly and short, too. On the bad side, it is repetitive, stupid, and frankly a bit boring to go to this soon after the riffing of the first two.
The others sound better as future MOT episodes. Especially, Warrior's Legacy 3 and 4 (with the Ryu/Sakura lemon short) sounds pretty interesting. ^_^
Chosen Warriors: Only good frankly if you MOT guys wanna do it. ^_^; Honestly, I think it'd be great if you tried to MST an entire impro series (technically, it's still unfinished. I should know... and get to finishing it. ^_^;). There'd be a bit of a comments on how the authors diverged, where the plot seemed to go nowhere, where the story goes "huh? WTF?!", and where the characters aren't consistently characterized. ^_^
I would think this won't fit with the Minesweeper short, though. Maybe a future ep?
If not, maybe IFR can tackle this, Woof? :P
W4's Ultra omake: I frankly forgot what the story's about. ^_^; I know I read this back when it was first posted, but I can't remember. If I remember correctly, though, it's as long as Long Dark Bottomless Well... which makes it as short as the Ryu/Sakura lemon?
...I don't know. Would two short fics be enough for the Loons Duo's time as Mads? It just doesn't soudn like their style. I think it would be more grand! ^_^
Pokemon MASTER: Hey, it's Pokemon! I can definitely see the Mads choosing this one, just to annoy those victims in the theater. ^_^ I haven't read it really, but from what I'm reading, it's silly enough to fit the motif. ^_^
So to summarize: I think Pokemon Master and the LBG/MK crossover are the best suggestions for this one. That's not to say the others can't make good future episodes, it's just that... well, I think they're the best that fits the style for the current Mads and cast.