There’s no great way to determine what’s most commonly used. There’s only some indirect proxies.
Most Downloaded Packages is one way to measure, but that’s based on downloading package binaries from packages.ros.org, which not everyone does, and doesn’t count if you downloaded from source. The website only lists the top ten for aesthetic reasons. I could post the current full list if desired.
The Repos Table sorts based on Github metrics (forks/stars/subs)
The ROS2 data was discussed on Discourse previously. I cannot speak to the difference between these numbers and the ones from packages.ros.org. If there are different ways of visualizing this data could be useful, please let me know by opening an issue