The first Marvel Fanfare was written by Brian Tyler for "Thor: Dark World" and is available on that soundtrack album.
The second version was composed by Michael Giacchino for "Doctor Strange" and has been the version used since. I don't think it's on any of the soundtrack albums.
I didn't realize there were two; I'm looking for the Giacchino fanfare, although the Brian Tyler one is quite nice. I'll need to check Spider Man: FFH and scour down more track listings if it's the same. Thanks guys!