They're all shit. Sky knew they had something different with Neville about 12 years ago - he had just finished playing, knew what it was like to play week in, week out in the premier league and had been a part of some hugely successful sides, so was, as others have mentioned a beath of fresh air at the time.
The problems started when they added Carragher (who is utterly fucking garbage) into the mix, it devolved from Neville trying to add an analytical/tactical view point into Rags vs Dippers. Keane's a prick, he's on sky because his soundbites and faux-miserable old man routine make him go viral. Redknapp looks like a dinosaur compared to the rest of them. Don't get me started on Richards.
There is no good pundit on mainstream television. Sky/BBC/TNT whoever can't run a pre-show or analysis without including and ex- Rag, Dipper or Tarquin - why do City's European games need coverage from Ferdinand, who hates us or Savage who never came close to playing in the champions league?
Football has become something Sky and co can market to 13 year olds with 10 second Tik tok attention spans, the era of analysis is over, they would much rather hear Micah make a fool of himself or Neville and Carragher argue.