It's funny this is a thread, because I got married October 30th and actually did play Final Fantasy music at my wedding! It was mixed in with some string versions of alternative rock songs, and it sounded beautiful. I downloaded most of them from EoFF, actually.

On the playlist:

-FFVIII - Eyes On Me (piano)
-FFIV - Rydia (Celtic Moon version)
-FFVI - Coin Song (piano)
-FFVIII - Fisherman's Horizon (piano)
-FFIV - Prologue (Celtic Moon version)
-FFIV - Theme Of Love Practice Track (Celtic Moon version)
-FFIV - Into the Darkness (Celtic Moon version)
-FFVIII - Ami (piano)

Definitely a lot of good stuff for a wedding from the Final Fantasy VIII or Final Fantasy IV - Celtic Moon soundtracks. I had to have "Eyes On Me." It's such a beautiful lovesong.