Mion - My favorite Higurashi character, and possibly character in any anime, through and through. To me she's the cutest (with Hanyuu and Satoko in tough competition) and funnest out of the cast, with her shy side, her ojisan side, her cosplay crazy side, her leader side - all mixed into one just plain awesome package. You can't find other characters like her. And I think Rayneing said it best, she's the go-to girl if you want a loyal friend - just look at how Rena and Shion both went to her (over, say, Keiichi or an adult) when they were worried about losing it.
Akasaka - Because he kicks butt, takes names, and well... he's just generally really awesome. (and totally a descendant of a Saiyan)
Hanyuu - Most moe moe blob ever. <3
Also voted for Keiichi, Satoko, and Ooishi for various reasons. I already loved her, but Satoko in the first two arcs was just... yeah. Kei-chan for all the reasons everybody already loves him - master of words, man among men, and all that jazz. And.. how can you NOT vote for Mister Delicious?
He's been one of my faves since waaaay back.
I
would have voted for Takano, if only because she was an outstanding villain, except... she kind of became rather... pathetic come the last three episodes and any respect I had for her was flushed down the toilet.
The other characters were all great, but yeah, gotta only pick a few or there'd be no point to the poll, yeah?