Amazon UK have reduced the standard Kindle to £59.99 but you can get it for £49.99 if you are a Prime customer and are in a Prime Now delivery area. Sorry it's a bit niche but I imagine populous parts of the UK should be covered by Now now?!
If you're not a Prime customer you probably know someone who is or can sign up for a free trial using a new account etc.
Same sort of deal for Kindle Paperwhite - reduced to £99.99 but further reduced to £89.99 with code (RRP £119.99).
The code can be used on any order of £50 or over.
More device deals in comments