My husband doesn't like tomato based sauces, so I use:
I often use coffee with spices for hardier meats (beef roasts).
Mushroom water (soak dry siitakes) is very flavorful.
The high fat crowd goes for cream.
Kefir or diluted yogurt/sor cream can work for a lot of dishes as well.
Oh, and wine of course, if you have wine.