Theme?

Tenga Toppa Gurren Lagann

Full Metal Alchemist: Brotherhood

you can watch the 2003 series first, but you don't have too

Cowboy Bebop

space bounty hunters with a bit of existential crisis

Baccano!

Tarintino esque journey on a train to new york

Katanaragi

unique art syle, hard to describe this one

Last Exile

Samurai Champloo

Samurai battles and a hip hop soundtrack, made by the creator of cowboy bebop

Rurouni Kenshin (aka Samurai X)