My strongest opening is the Ruy Lopez Exchange (I haven't lost with it in a USCF game yet)
I also play a heck of an alapin variation of the Sicilian defense.
For black, I'm a fan of the classical defense for QGD. I also use the Tarrasch from time to time.
I personally like playing d4 because i know the positions and they are not as dangerous. I love playing agianst e4 though slaughting them with a sicilain is so enjoyable ;)