Costco (in Canada at least) has these sweet rubber mats that remind me of the gym. Way cheaper than Amazon since they are heavy as heck! It's flat on the other side :
Supreme Garage Floor Tiles, 8-pack | Costco
G-Floor Slate Grey Ribbed Tread Roll Out Flooring, 7.5 ft. × 17 ft. | Costco
Thinking about getting rubber floor tiles for my garage. Good product y/n? : r/Costco