heartburnron: I'd like to build a spreadsheet of all my games and was wondering if any of you know of a way to get my lists of games out of Steam & GOG and into Excel? Purchase data would also be awesome if there is a way of getting this out?
Well, for GOG there is gogrepo or adalia fundamentals, do a search and you should find these. They are scripts for adding functionality to the website or downloading backup copies etc.
What I would say is this - and I say this after decades of doing this - don't use Excel. It may look appealing, simple to enter data and do various things. However it is not a database, I found that my sheet with several thousand rows on had somehow got sorted without sorting all the columns for instance. All that information was lost.
There are a few free collector programs, Sizimi for instance, or you could just build one in SQLite or something. I ended up, again after many years, buying collectorz.com's game collector (I got the higher one for multiple changes). I am reasonably happy with it, and I use the exported CSV output in Excel to do structure checks and such like. I would really like to move to LaunchBox which is currently free, and if you are just starting, would probably recommend you go have a look there first. Its free, has a lot of functionality, but is geared more to running roms through emulators. For my purposes where I have 20k records and now way of simply importing the metadata across, this isn't an option at the moment, which is a shame. But you starting off, start in either of one of these, or build it yourself, Excel will fail you at some point.