All types for all dogs!!!!
Structured walks or running (for older dogs) gives exercise plus benefit of bonding and leash obedience. Free play/exercise as dogs use different muscles and strengthen tendons/ligaments and joints by turning and galloping (things they can't do on a leash). Obedience or other mental exercise actually tires out dog faster than just exercise. This can be basic OB (I like to get my dog to do push ups. Lay, sit, lay, sit) or "find it games", agility, basically anything that requires the dog to think while exercising.
Just make sure you are well rounded in exercising and keep it age appropriate. Obviously a 12 week puppy should not do as much as a 12 month old or a 3 year old.
They all have benefits and their place in raising and keeping a healthy dog.