Most of Shang Tsung's Costumes
Liu Kang Zombie MKD
Reptile Lizard(Hey for MKA they should make him a ninja outfit but just showing his lizard face)
Mileena MKD
All of Quan Chi's costumes
Sub Zero's Alternate MKD
Rain MKA (Looks like a woman)....

MK1

I hate all of them. Especially Sub-Zero and Scorpion's.

MK2

Shang Tsung looked terrible
The "ninjas" looked a lot better

MK3

They were all awesome, even Shang Tsung's

MK1- Liu Kang (looks kinda plain)
MK2- None
UMK3- Shang Tsung (The hair, too >_MK4/G- Reptile (I don't like the look at all)
MKDA- Kitana's alt (She looks awful imo and pink doesn't fit her), Reptile's alt (no change), Bo Rai Cho's alt (disgusting) and Hsu Hao's alt (boring- only change of pants and no hat)
MKD- Scorpion's alt (looked ugly), Sub Zero's alt (awful! bald with a pony tail! DISGUSTING!) and Zombie Liu Kang
MKA- None

MK1: Johnny Cage (tw*t)
MK2: Johnny Cage(still a tw*t)
MK3: Stryker(Nerd)
MKT: Johnny Cage(still a tw*t)
MK4: Johnny Cage(midway should've gotten the message by now)
MK:DA: none
MK:D: Sub-Zero Alt (Come on!)
MK:A:None

MK3 - Kitana/Mileena/Jade. I'm so glad Midway designers got rid of their shitty buns. It made them look horrible. =_= Kitana looks especially bad in MKG,though.
UMK3/MKT - the Mighty Mortal Kombat Ninjas. Palette swaps are never good,especially when there is so freaking many of them.

MKDA:
Mavado Alt - what the hell is he supposed to be anyway?
Hsu Hao Alt - he looks horrendous without his cap on.
Li Mei Alt - come on,say it with me: "we wnat MK to bbe jsut liek DOA3 OLOLOL11!!!" I mean,she's practically wearing a bunch of napkins with some idiotic zipper thing in front. =_= What a piece of shit costume.
Frost Alt - same reason. Seriously,if you're trying to make a costume look sexy,just slapping a bra on and calling it a day won't cut it. Plus,she looks ugly without her mask on.
Jax Alt (the Homie outfit) - this is obviously a joke.
Kenshi Alt - this costume has absolutely nothing to do with Kenshi.
Reptile Alt (or was it regular? The one with the skull and bandages) - the idea is decent,but it simply doesn't look good on Reptile. Plus,considering that he is pretty much 85% green,those superficial details are barely noticeable,really.

MKD:
Sub-Zero Alt - because when I hear "nearly bald bum with a ponytail,"I think Sub-Zero.
Kira (both) - I just hate the character. What a waste of space. She has absolutely nothing going on for her with the exception of her enormous breasts.
Kenshi (regular) - it's far from being bad,actually,but it just looks inferior compared to the absolutely magnificent MKDA outfit. I eventually got used to it,though.
Nightwolf (both) - the regular one is barely different from his original MK3 outfit,and the alternative is a pathetic Chief Thunder ripoff with overly dark and unremarkable color palette. He just looks bland. Shame,really.
Sindel Alt - what the hell is she supposed to be? She the queen of the realm of Edenia,and she's going around wearing emo makeup and some sort of neogothic bikini thing. WTF?
Ermac Alt - the designers just made his hands bare and called it a day. =_=
Liu Kang Alt - instead of a fleshy pink thing (c) Krug,I would much rather prefer spirit Liu. *cue Spirit Liu theme song* Remember,he's supposed to be sort of dead,after all.

In MKDA, Hsu Hao's alternate makes Hsu Hao look like a bouncer on crack. I never understood Mavado and his costumes and in MKG Kitana looked like she was 50 yrs old.

Sonya's other outfit towards the end of the movie