Those are handhelds, not Nintendo handhelds.
Also, I don't know why you keep doing checkboxes when radio buttons would be the correct way to do these polls. I mean, for a favourite you shouldn't have more than one.
The Nintendo DS is by far my favourite. Although my first handheld was the Game Boy and my favourite handheld game of all time is Pokemon Red, it's just hard to deny the amazing software lineup for the DS. It's got the best variety and highest overall quality of any handheld system to date. The funny thing is, we have Sony to thank for that. The Game Gear was hardly any competition and every handheld literally was no competition to the Game Boy line. The PSP has finally forced Nintendo to step it up on the handheld front.
The GBA was great too but for some reason I didn't get into it that much. Might be because it was really my brother's system so all I ever bought for it was Zelda (tMC/aLttP), Tales of Phantasia, Advance Wars, and last Christmas: Pokemon Fire Red. He got the Golden Sun series though.