Which games did you choose?

[Ho-Oh]

Gen 1: Red, Blue, Yellow.
Gen 2: Gold, > Crystal.
Gen 3: Sapphire > Ruby > LeafGreen.
Gen 4: Pearl > HeartGold.
Gen 5: Black and White

I got R/B/Y at once, as well as B/W. I got everything else separately and that's basically the order.

 

[Strdstwanderer]

Gen I: Never got them, I did get them on emulators
Gen II : none, again on emulators
Gen I remakes : Firered and Leaf green
Gen III: Emerald and Sapphire
Gen IV : Platinum.
Gen II remakes: Heartgold
Gen V: Black

 

[blackmorale]

Gen I: Yellow
Gen II: Crystal (never reached the 1st gym, though)
Gen I remakes: LeafGreen
Gen III: Ruby
Gen IV: Diamond
Gen II remakes: SoulSilver
Gen V: ...I have yet to play games of this gen (waiting for B/W2 X3).

I think I played all versions at least once except for Gen II, Emerald, Pearl, HG and Gen V.