The best players play were the best players don't play.
I always liked that answer.
While I'm not sure it helps you avoid really good players, you can often avoid the risk of finding table full of tight players by looking at the rake. Low rake games tend to attract tight players. And tight players tend to avoid games with high rakes.
So, although it might be counter-intuitive in that high rake games present a large hurdle to overcome, the best games are often the games with the worst rakes. Those games tend to attract players who don't care enough about the rake to even think about it.
It was a Bill Rini post about the rake at WSEX that caused me to think about this.