Hideki and Chii {Chobits}
Chrno and Rosette {Chrno Crusade}
Yukito and Misuzu {AIR TV}
Yorito and Matsuri {Sola}
Renton and Eureka {Eureka 7}
Koyuki and Maho {BECK Mongolian Chop Squad}
Stein and Marie~! :D
And before you go shouting, "But it's NOT canon! Nothing happens with them!" read the fucking manga, people.
Read the fucking manga.