Logan's neither the worst nor the best
A lot of Gilmore Girls fans don't like Logan. It's understandable! I may have just called Dean entitled, but the entitlement really jumps out with Logan. He's from the wealthy world that Richard and Emily belong to, the world that Lorelai abandoned when she had Rory. He's reckless in a way that Dean and Jess never were because he knew he had a safety net to land on. (See: His dad's money.)
In that sense, I think a lot of viewers were on Lorelai's side about Logan. She never really warmed up to him, and for solid reasons. As much as she reminded him of boys she encountered in her past (maybe even Christopher), she also recognized had the potential to break Rory's heart from the beginning. It's on instinct that she kept her guard up with Logan. She stayed ready.
From the start, Logan was honest about who he was. He wasn't the monogamy type and wasn't interested in settling down. He was much more into living in the moment, jumping off tall somethings, and having the most fun. Eventually, Rory and Logan met in the middle and became a couple, but that wasn't the end of the drama. There were cheating allegations, stolen boats, laundry lists of concerns from Lorelai...
But I've always felt that Logan was unfairly judged by fans of the series. He arrived after Jess and a second-chance reunion with Dean; the odds were never really in his favor, were they? He was the third boyfriend late in the series that came in the line of succession after the fan-favorite love interest. Sure, he had his faults, but I always liked Logan. He challenged Rory and helped her to discover things about herself she might not have otherwise.