I agree with lenny6. OPS is a better indicator of a player's value, since it is a comprehensive statistic with aspects of ability to reach base and hitting with power. But if you're going to use it, why not use it as the only hitting category and eliminate all the others? AVG is a category that doesn't overlap much with the other 4 hitting categories.
Our league went 7x7, basically adding OPS but making it two categories by using OBP and TB.
For pitching, we like adding the holds category. Another category is stretching it, but we use home runs allowed. Another option could be TB allowed.