I think I was 20 years old when I got Golden Sun and Advance Wars... played so much of those two games, as well as the Zelda titles, Castlevania and Metroid.

I often wished that the later versions of the Nintendo DS had full GBA support, or that there were more titles available on the eShop for download... I was bummed to be miss out on being an early adopter of the 3DS and thus getting those exclusive GBA games that were never put up for sale afterwards.

But thankfully, like I mentioned in my other comment, the GBA emulation on the PSP is really good and that's now my main means of playing on the GBA when I want to (I even prefer it over the actual GBA SP I have).