I believe it to be a delicate combination of all of them. Most tomato based salsas have a bit of sweetness to them. As for chunkiness, the chunkier the better for me. The hearty bites burst forth with the freshness of the product, savory flavor can come from a dash of tomato paste, and spicy is always welcome. If you need a mild salsa, you shouldn't be eating it. Green chili salsa I believe should always be spicy and never sweet, the one exception to my previous statement.
It really is a matter of preference; know your guests and their preferences, and the flavors and components of the food it will be put on. Always remember, a salsa is meant to enhance, not over power or provide the flavor.
As with any food, it is a matter of one’s own opinion and desires.
As always, live light, eat well, and enjoy the bounty of the earth