Dance Games or Other Energy Burners

My 3yo has an indoor trampoline.

We all LOVE it! She got it from my dad for Christmas, and she has jumped on it for at least 30 minutes every. single. day. since then. It's especially nice for that last burst of energy before bed... I usually tell her that it's her last chance to jump for the day about 1/2 hour before we start our bedtime routine.

Ours is one of the bigger indoor ones... It takes up about half of her playroom, and is enclosed with a net. Before we got it, we just used her old crib mattress and made an enclosure for it with PVC pipe. Lol.

Jump ropes are good. My Dd doesn't quite have the coordination to use it right, but she has fun trying!

Use painters tape to make hopscotch, circles, etc. and let him hop around in them.

Another great one I found on Pinterest is to tape cheap paper streamers to he hallway, to make a "laser maze" to navigate through.

A few ideas off the top of my head:

Just Dance (Wii) is a very fun game for the whole family
Kinect Adventures (Kinect- need xbox) is also easy enough for small children but still fun for adults. And is quite a workout.
Twister (you know, the spotted mat game you put on the floor)
A mini trampoline (I have seen them super cheap on yardsale websites and it would be small enough to slide under the bed for storage)
Child's boxing gloves and punching bag- we just purchased from Toys R Us for our high-energy 6 year old
Make your own obstacle course- we often do this, using masking tape on the floor, hula hoops, pillows, very small handweights, etc. Sometimes we will use a timer. We just mark up the floor with the tape to make a balance beam, "x"s (jumping jacks right here), jump over the pillows, crawl through this tube, etc.
Make your own maze. Use yarn and tape to make a faux laser maze that you have to climb through, try not to touch the strings!
Lastly, YouTube has a ton of kid workout videos. Just type in "kid workout". Again, my youngest is just so high energy and wants to be moving constantly, and the long long winter is about doing her in. She likes to watch those videos and "get strong" and ya know, its not a bad idea to join in, lol!

You could also check into classes like gymnastics/jungle gym, karate, etc. or go to an indoor play place once a week.

I used to get great ideas from the public library - they have a whole bunch of DVDs you can borrow (usually a week for each one) with all kinds of fun activities. We also got a book of old style party games (stuff I played as a kid but forgot the rules for!) and used it for rainy days as well as birthday parties (we never hired birthday entertainers, bounce houses or any of that - we made our own fun). Sometimes there were craft ideas of things you could do with what's around the house. It's a great resource and one that's under-utilized.

You could try a low-tech game of "Twister" if the mat isn't too big for a child your kid's size. Otherwise go to the dollar store and buy a cheap shower curtain liner, and some paints from the craft store, and make your own. I know he won't know right from left, but who cares? He'll move and it will be fun while he learns his colors!

Nothing burns energy like playing in the snow.
Get him a snowsuit, mittens, snow boots and head out to the playground.
Besides playing on the usual playground equipment, he can make snow angels, make a snow fort, make a snow man, throw snow balls at a tree (or something inanimate), etc.
Take plenty of pictures!
When the summer heats up it'll be great to look over the cold weather pictures!

My kids play "exercise." My oldest tells the youngest what to do, and they run laps around the house, do push ups, etc. It's really funny, but it burns their energy.

It isn't as cold, so I'm sending them outside everyday.

At that age I had a smart cycle for my son. It's a plug n play cycle. You could probably get one pretty cheap from a mom to mom sale or thrift shop (not sold in store anymore). He really enjoyed it. We also had some workout videos for kids. Kick to get fit was his favorite (kickboxing for kids). We have an xbox with kinect. Waste of money. Unless you allow lots of screen time. The kinect has a hard time 'seeing' my 5 year old and she gets pretty frustrated.
I have a weighted hula hoop for myself and regular for the kids-those are fun and can be packed away in the closet. We also watch you tube work outs then use their ideas to make our own fitness routines.
A simple step And yoga ball are fun aerobic activities too.
I wouldnt do an indoor trampoline again. The kids ruined it within weeks and were always trying to pull it close to other objects to jump onto anytime they thought I was distracted/busy.
My mom has a small foldable manual treadmill. The kids love it when we are there and it takes some effort to get it moving!

When our girls were your son's age, they loved the indoor trampoline we got them from One Step Ahead. They also enjoyed the Move 'n' Groove Kids exercise DVDs.

I'm a get out of the house type of person. A change of scenery does wonders, especially during the long winter. Get him a toboggan and take him to the closest snow hill. Nothing burns off energy like walking up the hill and sliding down over and over and getting fresh air! I would also look at getting a membership for the YMCA. The Y usually has play structures, bouncers, drop in organized sports, free gym time with various equipment, and of course the pool. Swimming will usually wear a kid right out. I tried to discourage my kids from active play inside the house, I always told them to save it for outside or the gym