I ****ing love 80's music, I would love to participate in something like this.
To be honest though, I understand them not knowing Like A Prayer... I didn't hear it until like 4 months ago when I saw a thread about it here. Madonna is one of the few 80's artists I'm not into. I respect and appreciate her contribution to music, but I'm not that familiar with more than 5% of her discography.
Her albums in the 80s and 90s are sometimes a complete genre change from one era to the other. I suggest you go with her most acclaimed from those years first.