You do not have an easy decision.
I have both, each is a distinct game with it's own character, despite the theme.
SS is fun but often leaves me frustrated, hitting the start button again to try to finish on a "good" game. I don't have the skills to call the game easy, as I've never finished it, and as part of a collection it stays fresh, even if familiar. If you like to fiddly fart around and mod, SS has lots of cool add ons that enrich the visual aspect and sate the tinkerer in you.
EATPM is kitchy, fun, and leaves me smiling every time. Love the period electronic music and the total tongue in cheek feeling of the artwork and sound packages.
Dollar for dollar with current pricing, I think EATPM has more bang for the buck.
However, you owe it to yourself to own each at least once