Well Nick - that is a whole can of worms. Perfection is indeed in the eye of the beholder. There is a whole big debate as to wether or not to include beans. The amount of spice is very much up to your taste. This is my recipe that I teach to the kids at school
1 tablespoon Sunflower oil (do not bring)
1 medium size onion
1 teaspoon chilli powder (do not bring)
500g lean minced beef
14 oz can of chopped tomatoes
5 tablespoons tomato puree
15 oz can of red kidney beans
1 tablespoon Worcestershire sauce (do not bring)
1 teaspoon Wine vinegar (do not bring)
1 teaspoon sugar (do not bring)
salt and pepper (do not bring)
1 Chop the onions. Heal the oil in a pan.
2 Add the onion and cook for 3 minutes to soften.
3 Add the chilli powder and cook stirring, for 2 minutes
4 Add the mince and brown.
5 Stir in the tomatoes and tomato puree and then add all the remaining ingredients.
6 Bring to the boil, cover and simmer for 1 hour.
That could provide a base for you to work on. A number of the others use cubed meat instead of mince. The overall flavour can also be improved by adding a few squares of good dark chocolate.