Family unless the original Wii Sports

The range of new games is interesting / amusing; by cons, the practice of some of them (eg golf) implies that one performs more realistic movements (= closer to the actual practice of this sport): So, exit granny Ad First Wii sport that won the game with a slight wrist movement.
Younger children or very occasional players will also have greater difficulties to adapt and are likely to give very fast.
For cons, the 14 year old son is in his element; the only problem is that he goes around the issue in very few weeks.
Note also that the Wii motion plus is mandatory for each of the remotes used! So provide this additional investment or they will be able to play that solo.