Many of the paid anti-malware suites offer a free trial period. (If you find a company that doesn't
offer a free trial period I'd be suspicious. What are they trying to hide?) The free products are ... well, free. So you could certainly test different products to see which one(s) work best on your machine. It may help you make a more informed decision rather than relying on the very subjective opinions of other people.
After you evaluate one product, make sure you completely remove it before installing a different product. Many anti-malware products have their own official uninstall utility. If you fail to remove all remnants of one product, it could interfere with the successful install or operation of another product. Here's a list of official uninstallers. If you're testing something that's not listed, or if you're using a newer version, you could always visit the product website for the latest uninstall info. Security Software | SingularLabs