The Aquarium of Niagara is loads of fun for all ages. It's reasonably priced at less than $10 per person with children under 4 free.
It is fairly small and lacks some "luster" but what they have they do well. Upon walking up to the entrance there is a outdoor seal display where you can see the seals, a variety of them. If you'd like you can pay $5 to feed the seals at given feeding times which may be fun for older kids.
The aquarium is in the round and you walk in and the first attraction are the penguins. Penguins are a draw. Neat mammals to watch! Makes me want to go out and see that movie, "The March of the Penguins" which I've yet to see!
Then you look to your left and the "wall" is glass and you can see the BIG TANK with the sea lions swimming around. Very fun! The cool thing about the sea lions is that they have a "Sea Lion Show" throughout the day! You can view it from underneath (the window) or you can go "upstairs and watch "live". They do a bunch of cool tricks and routines that amuse children (adults too). It's not a long show which is good for the younger spectators.
Back downstairs there are a variety of fish, crabs, an electric eel, and lots of sealife! Lots of fun to wander and enjoy!
The Gift Shop looks nice and neat with fair prices but I can't say for sure because we skipped it yesterday!
They also have a program for schools or groups (Boy Scouts, birthday parties, etc) where they do a touch tank and tour and I think a private show.
Even though they don't have the "coolest" sealife, it's a neat place to go!
We're getting a family membership soon since we're nearby!