If you're looking for a cheap PlayStation Plus deal, the Rakuten voucher code is ready and waiting to net you a massive discount. ShopTo's marketplace is currently selling 12 months of subscription for £40, which becomes £30 with their wonderful code.
PlayStation Plus unlocks PS4 multiplayer, lets you download free PS4, PS3 and Vita games on the Instant Game Collection and grants access to a host of weekly discounts. The extra value can't be denied (technically it will pay for itself once you've downloaded and played a few games!), and this is the cheapest we've seen it in yonks. Remember that you'll need to make a full account to use the voucher, though. Thanks to TheMo123 @ HUKD!