Only 15?
Well, ok...
In no particular order...
1) Wonder Woman/Batman - Justice League
2) John/Teyla - SGA
3) Sam/Jack - SG1
4) Ron/Hermione - Harry Potter
5) Caspian/Susan - Narnia (movieverse)
6) Phedre/Joscelin - Kushiel books
7) Fry/Leela - Futurama
8) Anne/Gilbert - Anne of Green Gables-verse
9) Jack/Renee - 24
10) Piper/Leo - Charmed
11) Felicity/Gus - Road to Avonlea
12) Hawkgirl/Green Lantern - Justice League
13) Sydney/Vaughn - Alias
14) Mulder/Scully - X-Files
15) Booth/Brennan - Bones
Honorable mentions: Barney/Robin (HIMYM), Adama/Roslin (BSG), Charlie/Dani (Life)