If you are looking for the latest in the franchise, Helldivers 2 is the current focus of the community, featuring massive optimizations like the "Slim Build" which reduced its install size from 154GB to approximately 23GB to improve performance on modern hardware.
If your current installation is buggy, use the "Verify integrity of game files" feature in Steam to repair your build to the most stable version. Download Helldivers Build 05222021 OnLine
Sites claiming to host specific old builds for "Online" play frequently bundle malicious software. Getting the Official Experience If you are looking for the latest in