If you are looking for a cheap handheld game system, you really cant go wrong with the 2DS. Its great for smaller hands as it dont flip down and does practically everything the 3DS does (obviously without the 3D part) without the 3DS price tag.
Tesco currently have a 2DS Mario Kart bundle on sale for just £49.99 which i think is a great price for a main Christmas gift.
Even better is that the Tesco Clubcard Boost is currently on, and this 2DS is included! For £25 worth of points you could buy this.
One thing to bare in mind before anyone makes the same mistake i did. Mario Kart is pre installed, you wont get a separate game for it.
Stock is low so hurry if you want one.