Capcom announced their 20th Anniversary Mega Man X music collection recently for Japan, and just announced the track list of each disk in the package. Some of these include over 50 tracks, all from the various Mega Man X titles.
The pack includes 12 CDs featuring songs from Mega Man X through X8, Mega Man X Command Mission, Mega Man Maverick Hunter X, Mega Man X Cyber Mission, and Mega Man X2 Soul Raise. Each disk is listed below and links to the track list provided by Capcom.
The "Mega Man X Sound Box" will go for approximately $120 and can currently be preordered here.