I personally could relate to Mercury's shy attitude but I was no where near the study geek, genius, computer master she was. As Cass knows too well,Jupiter is my all time favorite sailor girl and I still to date have a big crush on that super sailor hottie.
I always found her character and her voice actor to be very appealing, and she didn't come off as anything but a strong, determined friend who was dedicated to her friends and was not snippy, rude, or sexed up or egotistical. The ego thing is what bothered me about Sailor Mars and occasionally Sailor Moon.
I also got drawn to the Jupiter that she was always the loneliest and never really settled with a good boyfriend, I know Venus, Pluto, and Saturn also never got boyfriends, but Jupiter's bugged me more because the fact she wanted a boyfriend was a running gag of sorts with her.
"Southern toons" seem to have a big crushing affect on me, Rogue from X-men the original 90's series I liked, but especially from loveable Bunnie Rabbot:
From the Sonic SATam cartoon series and Archie comics, I find her to be absolutely adorable.