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