Mine was a black Gameboy Advance when I was about 6 (I think i got it when it was fairly new looking back at its release date).
If I recall, my first game was Dokepon, if it wasn't then it was the first game I played properly on the console itself. I actually still have the console and the game and all of which are still in full working condition despite the age and wars they've both collectively been through. Sometimes I just like turn it on and get that nostalgic feeling, reminds me of playing it on the coach when I was on holiday in Italy.