I am making a 3 tier graduation cake and I just wanted to know what would look better? A 8in, 10in, and 12in, or an 8, 12, 16? The number of serves doesn't matter because I am also providing a larger sheet cake for extra servings.

8,10,12 ... i think its nice when its proportional

It depends on the look your trying to achieve. When cakes have a 2 inch difference they give the appearance of that tower look going straight up. The 4 inch diffence IMO looks better because you can really see the definition of the tierres.

HTH

........It depends on the look your trying to achieve. When cakes have a 2 inch difference they give the appearance of that tower look going straight up. The 4 inch diffence IMO looks better because you can really see the definition of the tierres..........

I whole-heartedly agree
Depending on how it is decorated the 4" difference can make it look more like a wedding cake so consider decoration carefully.
Also the 2" difference (8,10,12) will make transporting more, *much more*, difficult