Currently watching Shakugan no Shana, Hayate no Gotoku, Clannad, and Bleach.
I have a crapload of anime stored up to watch though, like Minami-Ke, Bamboo Blade, GunGrave, Sayonara Zetsubou Sensei, Karas, Sousei no Aquarion, NHK Ni Youkoso, Persona Trinity Soul, Prince of Tennis Semi Finals, and Sketchbook.
Super old stuff I have saved that I should've watched already but haven't are Full Metal Alchemist, Samurai Champloo, and Afro Samurai...
As for Higurashi... I watched the first and second seasons and loved the series as a whole. The first season scared the hell out of me, but the second season was amazing. You actually find out the reason for all the insane stuff in the first season.
But a third season? I heard about it, but I kept wondering, what exactly would the third season include? I felt like the second season wrapped up the series pretty well.