L&O was my favorite, but it really hasn't been great television since Jerry Orbach left the show. (He played Det. Lennie Briscoe.)
I like CSI, but don't care for CSI:NY and *hate* CSI:Miami. The Caine character is annoyingly self-righteous and Shatner-esque. Not sure if it's bad acting, bad writing, or a combination of both.