I don't remember specifically which ones, but a lot from the Teenage Dream era. They were all Top 10 hits for sure, but the discounting/remixing of some of them definitely propelled them to #1
I don't really remember at what point in time songs were discounted or which ones were, but something that will always stick out in mind is how "Born This Way" sold 1.1 mil cuz of the 99 cent discount. It would've debuted at #1 either way, but that steep of a discount had to have cost the label thousands...
