Patrick Jane and Teresa Lisbon (Simon Baker and Robin Tunney), The Mentalist
This partnership works because Lisbon isn't so skeptical that she won't give Jane enough room to use his unconventional (but effective) crime-solving methods. But most importantly, the partners always look out for one another, especially when one of them goes a little too far in pursuit of a nemesis (Red John for Jane, Tommy Volker for Lisbon). Are they in love? We're not so sure, but we love watching them work.