What type of icing for birthday cake

[Florabella]

I usually just do a buttercream icing on sponge, but what else could I use (need to bake and decorate tomorrow and serve on Tues)

I've just made an Oreo cream cheese icing for a chocolate cake. It's really nice, but I don't want to think how many calories are in it!

Buttercream or cream cheese icing are my favourite. I don't like sugar paste, royal or glace icing. Not too thick or it makes the cake sickly.