I use Marshmallow Fondant. It's easy to flavor and color and you control the consistency. I've used it on wedding cakes where other professionals have asked what it is and called me a liar when I told them it was fondant.
1# mini marshmallows, preferably Kraft brand
1Tbsp alcohol based CLEAR extract
*If you are dying the entire batch one color add the color here too
5 tsp water
2# sifted confectioners sugar on a well greased (think Crisco) heat proof work surface.
Pour the melted marshmallows into the sugar and start mixing, knead to make smooth, coat the outside with more shortening and store tightly wrapped overnight. microwave 10 seconds at a time to soften if needed before rolling.
The amount of water needed can vary day to day and between brands of sugar, you can add more after you start mixing or just stop kneading in the powdered sugar when it gets as stiff as you'd like.
You can make it in a Kitchen aid if you have a white coated paddle.
I used this MMF recipe on my youngest daughters wedding cake and I can tell you it is easy to make and use to both mask a cake and decorate with.
The secret is using cream, butter and real vanilla. I love the recipe below - it tastes awesome. Less sweet than marshmallow fondant. And it's easy to make. Maybe 15 minutes? You can speed up the process by cooling the gelatin mixture in a water bath. I also add quite a large dash of salt to enhance the flavours:
You can also go as far to add other flavours such as lemon, strawberry, etc.
It's too bad there is so much bad tasting fondant out there. It really gives it a bad name. There are some great brands though, like Paula mentioned, such as Fondarific, Satin Ice, and Choco-pan.
Cost wise, the home-made a lot cheaper if you buy all your ingredients in bulk, but you still need to account for labour costs. Home-made also might not offer the same stretch/blending abilities as pre-made fondant.