By far, in fact I think the SP should have been included. In terms of portability , form factor, gameplay, game library and design the GBA SP is hands down the greatest Handheld ever created.
i think the key to their success ( besides the innovative design of the DS and the HUGE stable of games for the GBA) has been their foresight with pricing..the psp tryin too hard to be everything.. a ipod killer , a portable dvd player killer and a gameboy killer...and succeedin at none.. PSP movies buss, and there is no 'must-have' title for the psp.. heck, for a platform that supposed to be mature by now,new games have slowed to a trickle, not so?