Start with Pearce Reserve/Banks Reserve as TheReview mentioned above and look for the cul-de-sacs around it. Such as (from Google Map): Ellis Pl, Hawke Pl/Ln, Hicks Pl, Parker St, Marnie Grove, etc (Kings Langley have lots of them :-) )
Ellis Place.Best culdesac location in kings langley Street is mostly owner occupied. Easy access to motorways and public transport. 30 sec walk to pierce reserve and cricket ground aswell as very popular bike track, basketball court and kids playarea and fitness training circuit!
Ellis Place is nice but Exeter Grove and Rosina Crescent hands down are the best streets in Kings Langley. It is a beautiful tree lined street with friendly neighbours and most of the homes are very well maintained!