If you could create the ultimate Doctor and companion combo...

Personally, the 2nd Doctor and Jamie are probably my favorite DW dynamic ever and the epitome of what a Doctor/companion relationship should be. (A strong bond, loyal, their strengths/weaknesses compliment each other well, great banter, etc.)

If you could mix/match any classic or new Doctor with any classic or new companion (up to 2 companions), what combo would you go with?

On the flip side, which Doctor/companion combination wouldn't get along too well in your opinion?