I like Jadzia for being a weird alien. Sure, I prefer Kira, Odo, Quark, Dukat and Garak as characters but they all act exactly like humans only with make-up on.
Star Trek needed more characters like Jadzia, even if the writers struggled with what to do with her. She's not greatly developed but she's still better developed than the majority of the TOS, TNG, VOY and ENT characters. I'll never get how somebody like Sulu can sit there, say "Aye sir!" for 3 seasons and be a fan favourite yet when the writers actually try to do aliens the fans tend to piss on 'em. I also like Neelix and Kes.