Amazon offers its Prime members Just Dance 4 for PlayStation 3 (pictured), Xbox 360, or Nintendo Wii for $19.99 with free shipping. (Non-members can spend $25 or more to qualify for free shipping; otherwise, shipping costs $4.98.) That's tied with our March mention and the lowest total price we could find by at least $4.

Update: Note that the PlayStation 3 version ships in two to three weeks.