I liked this one the best in the ones I have bought so far:
I got a buy one get one free coupon for the Dr.Oetker mug cake. So I bought a couple to give them a try.
They are very easy to make and each package makes two cakes. They don't look as good as the ones on the package, but overall weren't bad. We had ours with some vanilla ice cream.
I think I paid $1.99 for two packages, and other than a little milk you don't need to add anything else to the mix. Unless I can get them super cheap I probably won't be buying them again. They make a quick pudding.