I have a Game Boy Micro that I love. I love how small and cute it is (like my penis). I take it with me wherever I go, and I play it if I'm bored, riding the subway, or waiting for someone. People are not really familiar with the Game Boy Micro, so they think I'm playing on a phone.
Anyway, it just dawned on me that the Game Boy Advance is now "retro." The Nintendo DS has taken over the market, and people don't make games for the Game Boy Advance anymore. However, it's not old enough that cartridges for it are hard to find, so now is a good time to collect games for it. You can still find them relatively easily in Game Stop and eBay. And many famous franchises have been released for it over the years. Just a few that I already have: Ms. Pac-Man, Castlevania, Virtua Tennis, Bomberman, Super Puzzle Fighter, Mega Man, WarioWare, Final Fantasy, Harvest Moon... I'm sure I'm just scratching the surface. And you know, I bought several games for it that I already had in other systems just because they were portable.
As time goes on, and Nintendo releases a new portable system that is not compatible with the Game Boy Advance, people will appreciate the Game Boy Advance more and will remember it fondly. I already do. And I am not going to get rid of my Game Boy Advance cartridges. I will keep playing them, and will buy a few more games.