Which is first Index or Railgun????
Since FUNimation now has both A Certain Magical Index and A Certain Scientific Railgun. I am wondering which one is first to watch? I like to know this and I thank you.
In the case of Index & Railgun, the continuity is… tricky.
If you want to watch the shows in the order they were originally broadcast, then it's Index s1 > Railgun s1 > Index s2 > Railgun s2 > Index movie.
As far as the actual chronology of the series, however, that's where it gets hard. This should help explain things a little better: http://toarumajutsunoindex.wikia.com/wiki/Anime_Timeline#Toaru_Majutsu_no_Index_Movie
Basically, it breaks down to: Railgun I -> Index I AND Railgun II -> Index II, with the movie in between episodes 7 & 8 of Index II.
Hopefully that helps shed some light on everything.