Okay, well first of all I don't agree with the hoopla surrounding tv. I set no limits and my kids don't watch tv all day long. We start shows all the time and when the natives get restless I shut them off. We color, pretend, pull the furniture back and dance, use learning programs on the computer, take a walk, look at books, and once you add in breakfast, lunch, snack, and a quiet time that almost always turns into sleep time even for the older kids, there just isn't that much time for tv.
BUT, if your little one really loves tv, use it to your advantage. Sign up for cosmeo.com and get him onto learning documentaries. There are 30,000 of them from ages prek to a senior in highschool. They have almost any subject you can even think of.
It's really important that you teach him to finish what he starts and pick up his toys, crayons, coloring pages etc... between each activity. He doesn't get to do anything for 10 minutes and say he's done.
Get him on the computer .. www.starfall.com, www.morestarfall.com, and even look into getting him a subscription at www.time4learning. He'll know how to read to himself by the end of summer and he'll be able to enjoy his reading time more.
MOONWALK... Try and find a used moonwalk or buy one through a payment plan. For about 400-500 bucks you can have a huge moonwalk that he can bounce in. 5 year old boys need a LOT of physical exercise. The tunnels at McDonald's and Burger King are great too. Frisbie in the park, crochet in the park, walks.. all are great and take some time.