Getting married in mid September and have never stayed at an inclusive resort. Would prefer a more quite location and price is not an issue. Family member have suggested the Cancun area...Secrets Resorts and Hard Rock. Would appreciated suggestions from the group. Thanks in advance!

You might want to check the weather before confirming this trip.

September is the height of the rainy season in the coastal resorts of Mexico, both sides.

We've stayed in the Mayan (Cancun area), about 4 or 5 times in September and October and had great weather. A few rain storms that were welcomed but it is humid and hot, so know that going in.
The Secrets is adults only, so if there were no kids it would be a great choice. The Maroma and Akumal are there two highest end ones on amazing beaches, no reservations, unlimited a la cartes, no towel cards, no bracelets and really just wonderful. I would choose them if you could but they are pricey, so know that going in as well.
The Hard Rock has two properties. one in Cancun (which I don't love Cancun like I love the Mayan) and one in the Mayan which has a family section and an adults only section (heaven) so you could accommodate both types of clientele and you will be happy there I'm sure.
If budget is more of a concern and it's still adults only, have a look at the Valentin Imperial maya and if it's not adults only, have a look at the Palladium or Barceló if youw ant a large resort and if you want a small one, The Akumal Bay Beach Resort or a Dreams property.
Budget, how many people, ages, location are really important to narrow down the list as there are sooooo many to choose from in this area.