Kudos to nmcqueen469! That's a lot of freebies! Lots of good info in this thread for those who wish to absorb it. I will accept that there are some that may not be as particular about their paint and for them, the stuff from Costco or other big box stores will be perfectly sufficient. I've been ordering from Microfibertech when they first started making these towels available (must be nearly 15 years ago?). Also been a customer of detailersdomain (Phil) for quite a while as well. He does sell boutique products, but his knowledge and customer service is exceptional and his product line is excellent. Got a detailing problem, talk to him and he'll steer you straight. His motivation isn't to sell you a sham wow, it's to help you learn how to detail your car. If you enjoy it and you get the results you're looking for, you'll buy more product.
Another thing that wasn't made clear was there are different towels for different purposes. A glass MF towel typically has a very shallow nap and very little linting after the initial wash. I've been using a drying towel with a waffle weave pattern from Microfibertech for over a decade (just ordered a replacement Adams towel). I'll typically keep two levels of plush towels for polishing. One used for bulk removal of the polish or sealant, and another for the final buffing or detailing spray.
The initial cost is a little high, but these last a LONG time if you take care of them. I do have a few Costco towels in the mix too...for interiors and door jams and for wiping down the dog after he's come in from the rain.
Ultimately, the biggest source of the fine marring on the paint is how you wash and dry your car. Pay attention to that and the tools you use, and you'll keep your car looking great. And if you picked up your MF from one of the autoparts stores, throw them in the trash. I've never seen anything there that I would put within 5 feet of my paint.