Bella's restaurant is 100% worth going to. Complete formal wear is perferred, dinner is very reasonable (like, same as any big box restaurant like Kelsies which is garbage) and is amazing food.
I'm going to try out rock climbing in the next week or two. Museum of Civilization has iMax 3D that i want to check out too.
Lots of great ideas in this thread, keep them coming. And if any of you young fellers sees a volleyball tournament coming to Ottawa U or Gonk, let me know.