I'm a Chi Omega at Texas State. I think that we are definately the best. We are known for being smart, beautiful, fun, and the best all around. There is a saying that goes around the Texas State greek life that says:
"Date a Delta Zeta...Marry a Chi O!"
I'm not trying to be biased just to my sorority, but the other sororities that i've heard good things about are the Zeta's (Zeta Tau Alpha) and ADPi's (Alpha Delta Pi).
Good luck with rush! And be yourself. You will have so much fun no matter which chapter you end up in!