For me it’s probably adding Jabba to Star Wars. I know it seems like I misunderstood the question, but I think in addition to being hideous looking it is completely pointless. That is, even if it could be done flawlessly, look realistic, and not have Han climbing over Jabba, it serves no purpose and should be left out.

I think they even altered Greedo’s dialogue in the original editing process to cover the same territory as the Jabba scene since they knew they were cutting the Jabba scene so now it’s just redundant.

Boba’s presence is also completely pointless. Combined with his role in Jedi, he now seems to just hang out with Jabba all the time.