Personal System Sellers
When it comes to videogames, at some point you have to make a decision. If you want to play these wonderful things you have to acquire the hardware to be able to do it. Whether that be with your own cash, receiving it as a gift, borrowing a friend's etc.
For me that decision is ultimately always driven by the software, the games themselves. I go wherever the games I want to play the most are.
So these are the games that were the proverbial straw that broke the camel's back for me. The ones that pushed me to do the dang thing.
They aren't always the game I wanted the most (although in many cases they were), and they often aren't launch titles (although some certainly are), but they are the one that made it happen.
Honorable mentions: Sonic the Hedgehog and Halo: Combat Evolved. I liked both games but I didn't find them compelling enough and didn't find enough other exclusives I cared about to get into the Sega or Xbox ecosystems.