I kind of waver between different anime series, though my favorite are mecha. Yuusha Ou GaoGaiGar/King of Braves GaoGaiGar, Yuusha Keisatsu Jeidekka/Brave Police J-Decker, Brave Command Dagwon, and Brave of Gold Goldran. I also watch Claymore, Fullmetal Alchemist, Eyeshield 21, and Initial D. And I fully blame my sister for introducing me to the non-mecha anime series.
I've also watched Beyblade (original series only) and Yu-Gi-Oh! (again, only the original series. The new ones just got too wonky for my tastes). And certain Digimon series