Just wondered what are the best rear bulbs to use? im looking for some very bright ones

Brightness is determined by the wattage of the bulbs. Higher the wattage, brighter it will be. However I do find driving around that LED bulbs used in rear lights, although no brighter, seem more direct and defined. As a lorry driver I get to see all cars in all weather conditions and can say that the LED ones look the best and can be seen from further away.