http://www.ebay.co.uk/itm/60-HOZELOCK-GARDENA-GARDEN-HOSE-CONNECTOR-O-RINGS-SEALS-/380118012063?pt=UK_Home_Garden_GardenEquipment_HandTools_SM&hash=item5880cc909f
Never a had aproblem since fitting out my ro and di with Geka fittingshttp://www.easywatering.co.uk/acatalog/Hose_Connector_with_Geka_Style_Coupler.html
Ive been using the more expensive Hozelock ones (about £5 each) for about a year and they havent dripped once... mind you, I only use them on reel connection, all the other connections are made with jubilee clips.
Plastic mate