I guess Ill kick things off.
Starting with REVIVE 『Sac Ri Fice -サクリファイス-』was never released officially and only played live during a contest event to see who can guess how many times Haru says Sacrifice in this song (That aside an amazing song btw ^-^). The winner got a gift card or something. There are others as part of revive’s weird project thing they have but im too lazy to find each one it will take a while.
Another one is MERALOA - IDEA. Never studio release only has an MV and they played it at lives. Good song unfortunately all their music is limited live.
Dunno much of this band but i think Unsaw - SEVEN wasnt officially released and only played live. Anyone can correct me if i am wrong.
(Sorry for the typo)