The handheld
A handheld video game console is a lightweight, portable electronic device with a built-in screen, game controls, speakers and replaceable and/or rechargeable batteries or battery pack. These games are very retro and used to be extremely common. Now there is the I pod touch, Used commonly for music and app playing these are the cheapest are simplest way to play. This is also applicable to the iPod touch and other touch screen gaming devices.
http://store.apple.com/us/browse/home/shop_ipod/family/ipod_touch?afid=p219|GOUS&cid=AOS-US-KWG-HOLIDAYFY13
us.playstation.com/psvita/
http://store.apple.com/us/browse/home/shop_ipod/family/ipod_touch?afid=p219|GOUS&cid=AOS-US-KWG-HOLIDAYFY13
us.playstation.com/psvita/