Pity it's the very last day of this offer.
Best denomination obviously the $50, with 15% off its $42.50 and if you have Amex offer saved its further $10 off making it $32.50 for a $50 gift card! Original AmEx offer deal - Targeted
Best deal out I have seen I think, I saw some previously posted hovering at 30% off but don't think I've seen 35% before!
If you have android pay, make sure you use this with the relevant offer saved for double points, and off course don't forget fly-buys points on purchase!
Pretty sure the AmEx offer excludes gift cards.