Definately Neelix. I liked Phlox because his character seemed to have more edge to it so I felt that the obnoxious aspect to him was a bit dulled in perspective.
Neelix...OH my god. Especially towards the end he was so nice it made me gag. And he just wouldn't shut up. And he wouldn't stop helping ppl when they said to stop helping, like Tuvok.
I think a redeeming episode was when tuvok was hit with (yet another) mysterious energy beem and lost his logic. I kind of understood Neelix after that.
Though the last episode he was in he had some chutzpah, so i guess Phlox and him aren't TOTALLY different.