Easily Adam Laxalt since he was seen as the "strongest" GOP challenger by and large. But that was only a product of the others being that much worse rather than any strengths of his own. Laxalt was a nepotistic election denier without any real strengths of his own. He nearly lost in the red wave of 2014 in Nevada when about every other Republican was winning by double digits. Dude was not strong. He just looked a little more normal compared to the disaster artists that were Oz, Walker, Masters, and Bolduc.
I also think a lot of people on this forum (myself included) should learn a valuable lesson after this year: early voting data means jack squat. People here had Cortez-Masto DOA based on that. Go back and take a look at the posts.