I personally only use Duncan Hines.  I also love the Swiss Chocolate, and as someone else indicated, most stores don't carry it.  Don't know why.  I always buy it out when I can find it.  The French Vanilla is awesome.

AFor me, it depends on what cake I am making. I usually bake from scratch but if I want a dense cake I will use a WASC base. For chocolate I like Pillsbury traditional (no pudding) for white I like Duncan Hines French Vanilla.