Daniel linked to a number of awesome options:
The South West Coast Path
The Cleveland Way
The Norfolk Coast Path
Fife Coastal Path
Arran Coastal Way
Ayrshire Coastal Path
Causeway Coast Way
Lecale Way
But his personal pick for best U.K. coastal hike is the Pembrokeshire Coastal Path.
Andy’s added another on CheapTents.com:
Anglesey Coastal Path Walk
The Anglesey Coastal walk measures in at around 125 miles in total, though handily there are 20 towns/villages located directly on the route. This means taking on just part of the walk is easily done, making this walk accessible to most levels of walker at some point. Overall it took us 8 days walking to complete the full distance, plus one more day we spent in one of the villages on the route – from the information I can find it can take anywhere from 5 days to 2 weeks to complete the full distance.
We started walking from the Roman Fort (which encircles St Cybi’s Church in Holyhead), this is also the end point of the full circular walk. On the walk we saw some spectacular scenery, there is some really quite cool wildlife including; puffins, guillemots, seals and even the odd dolphin! as well as beautiful Anglesey coast line.

























