I recently posted
a blog post about this (scroll down to the bottom of it for the sports bras section). I'm a 30H and definitely need something super supportive!!!! I wear a Freya Active bra and it holds me up flawlessly!
Also, look at the links in the blog post for the Invest In Your Chest reviews of various sports bras.
Big thing I want to say, though. If you need a lot of support DON'T EVEN THINK ABOUT BUYING A SPORTS BRA THAT SELLS IN TERMS OF S, M, L, XL- ONLY BUY ACCORDING TO YOUR BRA SIZE!!!! Also, make sure you know that you're wearing the correct bra size otherwise you're going to get zero support!!! (your band=your underbust measured tightly!!!!) If you're wearing the wrong size you'll most likely have to go up some cup sizes.