The best choice for the beginner and advanced trader is definitely Mirus/NT+Zen-Fire/RCG Clearing. My account is with them.
Those who don´t want to pay the 60$ per month, can go with openecry. I traded with them before and no problems. The platform, the clearing and everything is excelent. The platform is pretty much like NT, and can be said that is even better then NT, but heavier for sure, and the feed is slightly slower than ZenFire. The account minimum is 5k and if you don´t have, you can go with atcbrokers, they are IB of openecry and the account minimum there is 2500$.
For proffesional traders, advantage futures seems to right choice. Personaly still don´t have experience with them.