Ole at the wheel aside I've always liked Rio funnily enough. You won't get a massive amount of in depth analysis out of him but he generally talks sense and avoids peddling the tired old cliché's. The BT lot in general are usually ok.
Sky have the worst pundits by far. Souness, Keane, Redknapp all belong in the trash heap. Neville was alright in small doses, at least as someone to disagree with, but with United's downfall he's become bitter and cartoonish. Carragher is alright.