My very favorite is coffee ice cream, with whipped cream topping. Once I was able to get "Coffee Chocolate Chip" in a Haagen Daz shop in the Dallas airport. Have no idea if it's still there.
When out getting frozen yogurt, I usually get small chips on top, plus chopped walnuts and whipped cream.
I'm not big on syrupy toppings. Too sweet. I'd rather the ice cream be the sweetest thing in the dish!