The batteries with the highest mAh rating will give you the longest run time.
Others have already said it. Many Chinese batteries have false ratings on them. They seem impressive, and increase sales. But they are scamming customers.
In the past, I bought some of these Chinese batteries. They worked fine, but I believe the actual mAh rating is now what is written on the side.
There are a lot of videos on youtube that show counterfeit 18650 where a small, much lower capacity cell is inserted in the shell of an 18650 with the terminals wired to the external poles, then packed with something like flour or sawdust. The battery reads the proper voltage, however the capacity is much lower than it should be.
I belong to a couple of flashlight forums. The primary one I visit is budget light forums (google it because I can't post links yet). A lot of very knowledgeable people are active there with a whole lot of information about batteries, flash lights, etc...