I've just got into the original series (and plan to watch the others), but I couldn't find any working links for the Sword Art Online soundtracks.
If anyone can help that would be great :)

Here you are friend https://www.reddit.com/r/swordartonline/comments/a8bi5v/upload_sword_art_online_the_collection_flac_maybe/
Care for "Music Collection" Aincrad to -> Calibur arc some are fake flac. (The true bitrate is 320)

And just search in ffshrine and ctrl + f for filtering. :) Cheers