I grew up and my parents still live 2 hours from the falls.
It all depends what you like to do....we always do Maid of the Mist (both sides), and Cave of the Winds (US side). I love both of these and consider them a must. If you are adults only there are Casinos (both sides) to have fun in...they are ok..nothing really fancy.
The canadian side has way more to do. They have an indoor water park for the kiddos...there are also many things on the "strip". Wax museums, Mazes, arcades etc. My mom always goes on a ladies trip up there and they shop at the outlets and eat lunch at the top of the tower.
They also have chain places as well as one of a kind places. Rainforest Cafe is there, along with Hard Rock. It is a place you can go and just pick what you want to do when when you get there.
All and all I feel it is a good place to visitat least once in your life...the falls are amazing.