Okay, brace yourselves, I'm a huge Fatality mark so I've got a lot of ideas here.
Firstly, even though I LOVE the 10 - 15 second long Fatalities, you're all making a good point. Having a quick and to the point 4 - 5 second one would be nice.
However, I want to overdose on Fatalities.
Fatality 1 (quick)
Fatality 2 (long)
Fatality 3 (long)
Animality (have to Mercy 'em first)
Brutality
Friendship
Hara-Kiri
Stage Fatalities
That's what I want. I mean, hell, if if Friendship's come back, I'd do them only against players I've had a good match with. Even better if they're brought back as a show of respect with maybe a bit of wackiness for certain characters (e.g. Scorpion nods approvingly before disappearing , Raiden heals them and bows before teleporting away, Quan Chi condescendingly says "You're a worthy adversary", The Cagemeister kindheartedly gives them an autograph). But for the ones that I want to relish my victory over, I want variety. Yeah, two is alright, but I want to be able to choose how I'm gonna finish 'em off instead of picking one over the other because I prefer one more. That happened a lot for me in MK9. The only Fatality I would ever really do with my home boy Ermac was his "Mind Over Splatter" one because "Pest Control" was just kinda dumb. Fun to kind of belittle someone at times, but still dumb.
And bring back Hara-Kiri's as a time specific thing. If the winner doesn't finish 'em off in the first two of five seconds of input time, the loser can just off themselves there and then to take away the opportunity. I'd like to think it'd stop online douchebaggery like tea-bagging, but there's gonna be some way of showing disrespect whether we all like it or not.
For Brutalities, have them be exactly that. Brutal. Make it a Ultimate Combo kinda thing (again, another good idea from this thread) that starts as a BnB or whatever and evolves into a cut-scene where the winner viciously beats the opponent to death. Add some flare to it by having the victor look and act infuriated (roaring, breathing heavily, swearing etc.). And please don't let them end with the loser being blown to smithereens. That was fine for 1995, but it's 2014 hahaha
Animalities I'd love to see just for the potential they have with today's technology. Have them be hard to pull of, though, like having to Mercy 'em first. Just imagine. You've won with Quan Chi, done a Mercy and then watch as Quaners morphs into a morbid and horrifying insect like creature made of bones or something that wraps itself around the loser, slowly crushing them into a human tube of toothpaste.
But hey, that's just my wishlist. So long as I'm given a bit of variety with Fatalities, I'll be happy.