Funnily enough I just posted a similar thread, my first thread - http://www.specktra.net/t/182673/holy-grail-foundation-for-woc-or-do-you-like-me-have-a-problem-really-figuring-out-what-really-really-is-the-right-shade-for-different-occasions-day-night-pictures
What kind of skin do you have (dry, normal, combination, oily, etc?)
I have oily skin, so I sometimes use Revlon ColorStay for Combination/Normal/Oily Skin which has I think 20 shades, but they also have a Revlon ColorStay for Dry/Normal Skin but I don't know if that has as many shades. For a drugstore brand, I think ColorStay is a great value. I got mine at Ulta.
If you want to spend more, you may want to check out Make Up For Ever, sold at Sephora.
My personal favorite is Mary Kay Medium Coverage Foundation but I think it is for combination / oily skin, I don't know if that describes you. It's the most natural looking on me. You may want to try it out anyway even if you are not combination / oily because it isn't really too mattifying, I don't think. Since Mary Kay not really sold it might be a little difficult find a sample to find your color if you don't anyone that sells it. I know my color so I bought new ones on Ebay for cheap. I saw samples being sold there too so you might want to buy a few sample cards to test out. Also I have seen some Mary Kay being sold in a beauty supply but I don't know how many do that.