In Phantasy Star I; Odin had his uses, definitely, but he could have been a lot better than he was. He was really accurate, though.
In Phantasy Star II, I never really found that much of a use for Hugh, since his techs only work on biomonsters. I probably should have given him more of a chance though.
PSIII and PSIV: I didn't get far enough to tell. Damn school work.