Gen 1: I got Pokemon Blue. I wasn't around for Gen 1's original release so I had to get the VC versions. Either way, I prefer Blue as a colour to Red
Gen 2: I don't remember but I chose Silver
Gen 3: I got Ruby. I thought Groudon looked really cool at the time.
Gen 4: I got Diamond and I preferred Dialga's design. Diamonds were also really valueable so there is that.
Gen 5: I chose Black and I don't remember why
Gen 6: I chose Pokemon Y because my friend was getting X. I choose Alpha Sapphire because my original Gen 3 game was Ruby.
Overall I think that the box legend has the most influence over which version I choose. For Gen 7 I'm going Moon because Lunala looks amazing.
Gen 2: I don't remember but I chose Silver
Gen 3: I got Ruby. I thought Groudon looked really cool at the time.
Gen 4: I got Diamond and I preferred Dialga's design. Diamonds were also really valueable so there is that.
Gen 5: I chose Black and I don't remember why
Gen 6: I chose Pokemon Y because my friend was getting X. I choose Alpha Sapphire because my original Gen 3 game was Ruby.
Overall I think that the box legend has the most influence over which version I choose. For Gen 7 I'm going Moon because Lunala looks amazing.