The Five Pasta Sauces

A while back I got a note asking me to identify the "five (5) basic pasta sauces."
There really aren't five sauces per se, though I suppose one could establish five categories of pasta sauces: Red sauces, meat sauces (with or without tomato), vegetable sauces, fish sauces, and cream sauces.

However, within the categories what's basic will vary with the season. For example, among oil-based sauces, in the winter you might want a creamy cheese sauce, whereas in summer a simple aio olio (garlic, olive oil, and hot pepper) will be more refreshing. Or, among meat-based sauces, in winter you might want a rich Bolognese sauce or a Neapolitan ragù, whereas in summer an amatriciana will be more likely to hit the spot.