NE146

That's why I generally refuse to get into another store, like Desura or Direct2Drive, since I won't know where to look. Humble, GOG, and Steam all are easy enough to navigate, and have 99% of what I would want anyway. I've used the Steam calculators and they show that I would need like 7 lifetimes in order to finish what I have now.

I keep a spreadsheet. It was painful at first, but is well worth it now that I have thousands of digital titles in various stores (although I do tend to try to keep most such purchases to Steam unless there's no way to avoid it).