Rock Auto is a good website, but I would stay away from the parts in the "economy" section in general. Anything that's "standard replacement" or higher is recommended. However, I wouldn't look at the "economy" or "standard replacement" categories. I would look at the manufacturer of the part and research whether that manufacturer makes the OEM parts for your vehicle. 

For example, if I wanted to buy replacement ignition coils for my 2016 BMW 428i, I would look for ones manufactured by DELPHI because those are the OEM ones on the car right now. But then you may see multiple ignition coil options by DELPHI (different looks), so you would want to match the look of your original ignition coil with the picture. I also know that NGK is a good aftermarket manufacturer for ignition coils (and ignition systems in general), so I could also buy those depending on the pricing between DELPHI and NGK.

It's all about knowing the manufacturers, not so much about the website's ratings for parts.

I like Rock Auto and Car Geek but like Razmig said, stay away from the economy section.  I always try to get parts with a "limited lifetime warranty" if possible.

I go to Rock Auto primarily.  Sometimes if a part is not there for my GM vehicles I order from https://www.gmpartswarehouse.com

Thanks!