1. Giant Gonzalez - Whether he was just unable, or too stupid, or whatever it was, there was no selling whatsoever. I guess being as big as he was it wasn't too unbelievable that maybe he wouldn't be phased by much, but it was still horrible.
2. Goldberg - Yeah, get pissed for all I care, Goldberg sucked at everything except making dumb fucking faces and hitting his finish. He didn't sell for shit at any point, and it made everyone he wrestled look bad as a result. FUCK GOLDBERG. That's my stance, it always has been, never will change. He was a disgrace to wrestling.
3. Great Khali - It's easy to pick on the giants, but it's also accurate. Khali doesn't sell well and that poor bastard's been made to job out to all kinds of people. You'd think by now he'd figure something out, but like Gonzalez he's probably just to big and cumbersome to really make it look good without making it look fake and over exaggerated as well.
4. Ultimate Warrior - I might be stretching a bit here with Warrior, but it's true that for a long time he was pretty shitty in the ring and part of that extended into his ability to sell his opponents offense. Now his character wasn't the type to be dominated or by hurt REALLY bad by much, but he still just wasn't good at it even when he was supposed to. Eventually Warrior did develop into a solid wrestler, not brilliant by any means, more of a showman as he always was but eventually he was able to put on a decent match. For the majority of his time though, he was outright horrible at selling.
5. Old School Undertaker - Once again, big guy, gimmick doesn't really constitute being a great salesman, but it was still SHIT! Granted, Mark Callaway wasn't exactly a tenured vet yet either, he was still pretty green honestly, buuuuut that doesn't entirely excuse the shitty selling. He's a piece of enlightenment; part of the reason his gimmick consisted of him being relatively impervious to damage was to mask the fact that he wasn't very good in the ring. That tells you something right there, he just wasn't there yet as an in-ring performer. Great gimmick, he played it well, but not a great salesman when it came to opponents offense.