I'll just put down some of the series I've watched and liked:
Trigun, Eureka Seven, Ghost in the Shell: Stand Alone Complex, Wolf's Rain, Last Exile, Rosario + Vampire, Berserk, Gosyusho Sama Ninomiya Kun, Elfen Lied, Black Lagoon, Chobits, Hellsing, Claymore, Code Geass, Full Metal Panic!, Full Metal Alchemist, Serial Lain Experiments, Ergo Proxy, Sola, Inukami!, Love Hina, Girls Bravo, FLCL, Lucky Star, The Melancholy Of Haruhi Suzumiya, Death Note, Shin Chan, RahXephon, Gurren Lagann, Berserk, Love Love?, Vampire Knight, Soul Eater, Monster, Bokusatsu Tenshi Dokuro-chan, Kenichi
The mecha ones out of that are: Eureka Seven, Code Geass, Full Metal Panic!, RahXephon, and Gurren Lagann.