3 stick out for me. Mentioned it in another thread.
1. Superman on the NES. After playing Superman at the arcade and then seeing this.... SHIT. Super Mario type shit for a Superman game? And that damn looping "music" I can still remember that shit after all these years. If I'd get sent to hell, Satan would probably think it funny to play it loud to me for eternity. I would murder Satan for that bullshit.
2. Fatal Fury on the SNES. After seeing the arcade Neo Geo version, thought "This could be alright on an SNES, with what Capcom did porting SFII to the SNES..." HOLY SHIT were we wrong. Loading on a cartridge? Fucking loading??!!! Oh and it said "WAITING..." Bad sound effects and shitty "music". Put Joe and Micheal Max against one another. Joe throwing a hurricane upper goes "HAH!" Micheal Max throwing one goes "YO!" So you'd hear: HAH! YO! HAH! YO! WTF!!! God that game was such shit. I couldn't ever accept Takara doing the other Neo ports they did.
3. Pit Fighter on the SNES. Pit Fighter at the arcade gets ripped nowadays, but everyone back then; most people played it. It was slim pickings before SFII came out. Especially when most arcades didn't care to have big varities of games.
The Genesis version, people are small, and 2 players instead of three. Gameplay like the arcade, kinda. Lets see what the SNES is gonna do. Bad everything, no lifebars, numbers. Seriously, bad everything. I mean, it wouldn't have taken a low bar to get decent port of a bad game, but these fuckers were like lets make it even worse.