Didn't happen to me but I'm running LINUX so the shitware just bounces off. And I generally can't tell if a site is going to try to install something unless it asks to install an .exe which won't run on LINUX anyway.
With rapidgator just make sure to uncheck the box that says "use downloader" and it will give the plain .MP4 instead of trying to install its proprietary downloader (which I'm guessing is what it tried to do to you.)
