I bought them all, since they were about $55 for the set, which is a killer deal, but if you had to only pick a couple, then I would say to go with what your market calls for.  The medium and light colors are the ones I use most in my market (LA) but I am not sure, of course, about yours.  If you can spare the $55 or so that they cost, I would definitely get them all, because I use the darker ones as contour and bronzer colors.  I LOVE the consistency and pigment on these.  I'm a little obsessed =)

I hope that helps a bit.