I voted

Off-leash running (or on a long leash)
Playing inside (squeekies, rawhides...)
Playing outside (frisbee, ball...)
Swimming (or wading, if your dog is not a swimmer)

We have a lake nearby and when it was warmer we'd make at least a trip a week and Jamie would just swim swim swim!! Charlie is a wader, he doesn't like swimming, and I have to keep him on a leash hehe. Jamie also LOOVEEESS just running. For no reason. Just... running! And they BOTH LOVE playing outside with sticks (you know the "you can't get me! na na na nana na") but I think we MOSTLY play inside and outside