I'd love a big button I could click that says "Don't know what to play -CLICK HERE-" and have it roulette my library ...

Cuz then I wouldn't be sitting here stoned on Friday scrolling through 600 thumbnails trying to decide

Has been suggested a number of times before:
https://www.gog.com/forum/general_beta_gog_galaxy_2.0/a_silly_request_launchinstall_random_game

But yes, that would be wonderful.:)