The dinos were very cool, and definitely worth the visit if your little ones are into dinosaurs. There's lots of cool tech to go along with them to help explain everything. The bat cave is a perennial favourite, I even remember it from my days of trips to the ROM!
Given the boy's newest love for knights, we also had to make a trip to see different types of armour. We found this great collection of different styles from the 17th century, including a Samurai helmet, Mughal armour and Indian dagger & sword. He even got to dress up in something replica medieval armour, including a helmet & breastplate which nearly made him fall over it was so heavy!
That's why I love places like the ROM, whatever your interest, dinos, natural history, knights, ancient Egypt, or ancient Rome, there's something there to help spark your imagination, and inspire questions. Of course with the boy, it doesn't always take a lot to inspire a question! And some days with all the questions he asks, maybe I shouldn't be giving him fodder for more!