Anime
1) Evangelion (I don't see this ever changing)
2) Gurren Lagann
3) Cowboy Beebop
4) Trigun
5) Full Metal Alchemist (Both old and new)
Manga
1) Watashi no Messiah-sama (So many people overlook this epic manga)
2) Blade of the immortal
3) Mirai Nikki
4) Sundome
5) The Sandcastle
The manga section was particularly hard since the manga I'm currently reading isn't finished. The only exception I put on the list was the sandcastle because it was made in the 70s, but hasn't been completely translated.