Yeah I don't think Lisa is the worst winner ever but I think the fact that she was up against Danielle it makes her look even worse because Danielle was clearly the best player that season and totally deserved the crown.
Another winner, that I go back and forth on, but I'm currently in the mindset that he was a bad winner is Evel Dick. I've been watching back Season 8 and he was awesome at competitions I'll give him that, but strategically he was quite bad. The beginning of the game he was really off the mark with his assumptions, all pally with Amber and Dustin, getting confused by Eric's hicky votes and assuming first that Jen did them and then that Nick did them. He also had the huge advantage of his daughter been in the house with him, whether they spoke to each other or not, that is family and no way were they voting each other out. And also he had America working for him through Eric.
I remember at the time people saying the season was fixed in Dick's favour but I didn't really see it, maybe because it was the first season of BBUSA I'd ever watched but going back it really does seem set up for him and Daniele to make it to the end together.