Costas is the worst. It is the wild pretentiousness, and open mockery of analytics (and I am not saying that you should sing hymns of praise, but if a business reporter did not understand how analysts rated stocks today, they would be fired) and their tacit assertion that the old days were better which makes it hard to watch. Of the national guys, they hit on something good with Joe Buck and Smoltz.
The Sunday Night broadcast is fun too - Vasgergian is a pro, the TV version of A-Rod is terrific (essentially a gigantic dork about baseball) and Jessica is a good glue-guy/gal.