There are several varieties of insect-resistance traits, multiple brands of herbicide resistance (off the top of my head there’s Roundup Ready and Liberty Link), drought resistance, and several more. I was last deeply interested around 2008 so my knowledge is stale.
I found this USDA data sheet that lists a bunch of varieties for corn; others exist for the other GMO crops: https://www.ams.usda.gov/sites/default/files/media/BECornCro...
Watching the path-dependent nature of technology is fascinating. It seems Monsanto has largely given up on GMOs, due to public backlash, just as crispr and the like are set to make the whole endeavor a lot more precise. https://www.motherjones.com/food/2014/01/monsanto-gmo-techno...
The hot new thing these days (as I understand it, I am not a farmer) is precision ag - better use of maps, sensors, drones, robotics, etc to make better use of resources and better target chemical application. Bayer’s marketing site is probably a good place to get the farmer’s perspective: https://www.cropscience.bayer.com/innovations/data-science/d...