I'm a DD now, which I'm happy with since I ballooned to a 38-H (yeah, got ya beat Nuck
) when nursing and they never really settled back down till I lost a ton of weight, 80lb. But I was in an H for over 7 years, I think anything smaller than what I have now would look awkward on my body (to me, at least - my husband would be in heaven if I was down to a C, or even LESS!!!)
Word of advice on getting sized - yes it's crucial but DON'T go to Victoria's Secret!! They will purposely under-size you just to make sure "oh yeah you'll fit into our bras!" Go to a reputable department store such as Macy's or Nordstrom where they TRAIN bra-fitters to PROPERLY size a woman, and where they aren't afraid to say "I'm sorry we don't carry your size here, but there's a specialty shop at this address that can help you"
And you can TOTALLY get cute bras in the really large sizes, you just have to be willing to pay for them. I LOVE Fantasie bras but they're upwards of $70 each