Use? DS, GBA, with SNES/NES emulation capabilities being an added bonus
Price Range? < $100
Slot 1/2? 1
Built in or expandable memory? Doesn't really matter to me, personally.
Other? It's a 'phat' DS.
For all slot-1's (ignore if you want a slot-2):
Support slot-2 GBA? Yes
Support slot-2 rumble...