I would go for a DSlite if you can afford it, but other then that:
YES!!!
I game most on my DS. Touchscreen is absolutely awesome and provides some amazing games like Hotel Dusk and Professor Layton. If you're into RPGs it's the #1 platform and for most other genres it's an amazing system.
GBA games play very well.
I think every gamer should have a DS. No wait... EVERYONE should have a DS.