I came here quite a few times when I was a kid, and had some good times. Went back today, and some of the thrill is gone for sure. The leviathan is definitely a great addition to the park, and is probably the best ride. Psyclone is also pretty sweet.
The problem with the park is they are all about gouging you, which shouldn't be a surprise, but its park policy that they can't serve you a cup of water. Its illegal for a restaurant to do this, but a Starbucks in Canada's wonderland is above the law. Also the food is a rip off. I recommend going to the subway just outside the park on Jane st. The lines can also get really long, and if you've been to Cedar Point before its definitely not as good. A lot of rides lack magic and imagination, though Thunder Run will always be a fav of mine as it has a little bit of that going on.