The Mr. and I came here almost over a year ago on a date night partially for my birthday because of my love for aquariums (and then we had sushi after...don't hurt us). But I've been to many aquariums around the world and our own 6ix has one of the best ones in the world.
We bought our tickets online and there was barely a wait. The aquarium itself isn't that huge but it is a good walk around. The best parts are the jellyfish wall and the tunnel where you go to look at all the fish including sharks!
We didn't have their food because it just seemed overpriced and didn't appeal to us at all. However, Ripley's is definitely worth a visit for anyone visiting Toronto or for any locals who have never been!