It's sometimes hard to cough up the extra cash for tickets to experience landmarks such as this, but I must say it's worth it to at least go once. The view from the top is breathtaking and it really proves the vastness of Toronto. Apparently the CN Tower is the home of the highest wine cellar, which is kind of cool. And if you're really feeling fancy, they offer a unique dining experience at the top. My favorite view of the tower was actually from Toronto Island, so definitely go there to get an amazing shot of the city.
But in all honesty, if you've never gone up in the tower, be a tourist for a day and make it happen. :)