I loooove my PSP... I love it so much I bought a new one right after I lost my first one (fell off a boat
.. had a new 4gb memory stick and game cd in it too
but I bought a new one and hacked it.... I loooove it.... heck, PSP "fat" has TV out, like the new PSP Slip has... of course PSP Slim's tv out is better..
But, if I have to choose from the list... I'd say Commodore 64
, which I play alot on the PSP... all of the above systems can be played on the PSP, without speed loss or anything.