My first G3 Pony was Tink-a-Tink-a-Too and I remember that I loved her so much! I believe my parents bought her for me together with a tiny tin Pinkie Pie who also I adored!
I ended up kinda destroying Tink-a-Tink-a-Too by painting extra eyeliner on her and trimming her mane and tail so later I re-bought another one from Ebay as an adult.

I bought my first G1 Pony from ebay as an adult and it was Gusty since I loved her design and Pose!
Both Gusty and Tink-a-Tink-a-Too are some of my favorite ponies!
I can't remember who was my first G2 Pony because I think I found a bunch of them together at a flea market.