I've been coming to Toronto on business for more than twenty years, and love the city. I've seen a lot of it, but sad to say did not know the ROM existed. Then my wife spotted an item in a magazine about their Mesopotamian exhibit, a fave subject of mine. So next time on business I came in half a day early just to check the place out. It comes off to me like a smaller version of Chicago's excellent Field Museum. Their ancient Asian exhibit is great, the Egyptian stuff is great, and the Mesopotamian exhibit was FANTASTIC. Well organized, large, can't say enough about it.
Even the food in their cafeteria is good (had the mac and cheese). Their gift shops were also very interesting. I highly recommend this place.