When I saw this thread I instantly thought of my import of Arcana Heart 3 or even the upcoming Xillia CE (dat price...) but even those don't get to the highs of how much I've spent on Hyperdimension Neptunia V. Not only did I buy two copies of the game, one regular edition for $49.99 and the LE from NISA store for around $64.99. That alone jacks it up higher than any other game yet I've bought. Now, lets factor in all the numerous Hyperdimension Neptunia V DLC, such as secret dungeons, items, bikinis alts, weapons, armor, etc. etc. and...man.
Neptunia series has my soul...