This place is nice, beautiful but is something you can pass while visiting Toronto. Living in Toronto my whole life I've always wanted to go to the CN Tower. Now that I have it's nothing but a view.
Take your family and friends here when they visit just so they can say they've been to the CN Tower.
Keep in mind this place is EXPENSIVE, you can ride to the observation deck, but you will have to pay more to go to the top. There's also the 360 restaurant which I heard was expensive but covers the admission cost when you order a certain amount. So that might be worth it for a large group since one entree will be close to the same cost as a ticket. Go during a clear sky day or evening/sunset/night time for optimal viewing.