I have so many frosting recipes on this site! Some frostings are perfected classics like my vanilla buttercream frosting and my chocolate cream cheese frosting, while others are way more unique like cookie dough frosting. You can use any of these frostings as a cupcake frosting or a cake frosting. People often wonder about the difference between frosting and icing. I consider a frosting to be something that has height and can be piped with a piping bag while icing is more flat. I have both frosting recipes and icing recipes here.
My vanilla buttercream is an American buttercream made with powdered sugar and butter. If you like a less sweet frosting without powdered sugar and you want fluffy frosting, I suggest using a meringue-based frosting. My guide to Swiss, Italian, and French buttercreams should help with that.
I also LOVE using ganache (a combination of chocolate and cream) as frosting.
Some of my favorite frosting recipes are whipped cream frostings. To make them, you whip heavy whipping cream and then add whatever flavors you want. I love my strawberry whipped cream frosting!