If you have a dog that enjoys chasing things or running, one of the best toys you could get him/ her is a Flirt Pole.
A Flirt Pole is basically a long stick with a string attached at the end of the stick, and a toy attached to the end of the string. There are many you can buy online, but I recommend going to your local hardware store and making your own. Be sure to put the toy away when you are not using it WITH your dog. (Or remove the toy at the end and put the rest of it away.)