My favorite was definitely Flannery. One of the only videogame characters I ever had a crush on. I would have redacted taken her to a nice seafood dinner then called her back after observing the 3-day rule.
A very close second (and if we aren't counting looks, my first choice) is Wattson. Electric is one of my favorite types, and I like the jolly old man character he has. He just seems so... friendly.
Least favorite was Tate & Liza. The dual battle gym mechanic was fun and all, but that Claydol/Xatu combo was a redacted again tough fight.