Antec DF-series is a good bet. The DF-30 will hold your components with ease, so I'd recommend it with a smile. I have one myself, and I can hold true to that. It's not too big externally, but it has a surprisingly large space inside. The HDD bays are accessible from the front, so installing/removing HDD's is a breeze, specially with huge GFX card setups (like a dual-GTX560 setup).
Really good case, good cooling and very nice looks. If you don't appeal to the blue/black theme, look at the DF-35. It's the same case, but with a black finish and white LED's instead of blue ones in the fans.
You are correct Toxxyc.. The Antec 1200 is surely a full tower case.. And that's the reason i've mentioned it separately and not grouped it with the other mid towers that I have suggested.. Its a good case for an awesome price and since it fits inside OP's budget, I was compelled on mentioning it (in spite of OP clearly mentioning that he is looking for a mid tower)..