Just bought a Wii U? Hit the ground running with the handy Wii U Accessory Starter Pack for just £3.00!
It includes a Neoprene GamePad case, Wii U Stylus, standard Stylus, Screen Protector Applicator and Cleaning Cloth. You'll definitely want to keep a spare stylus and cleaning cloth handy, especially if your kids frequently use it, while the screen protector and Neoprene case should help guard the GamePad against wear and tear. It's a pricey bit of kit, so £3 is probably a decent investment.
Note that you'll need to reserve and collect in store to avoid paying extra delivery. Many thanks to jamesianmoore @ HUKD!