For hockey pucks visiting the city, you’ll be hitting the HHOF obviously (and it is a must see for sure). Some places that haven’t been mentioned:
Eating / Drinking
Old Spaghetti Factory - it’s an old institution that’s been around for a very long time in Toronto, and has a unique and funky, decor inside and servers up excellent Italian food.
Nearby/besides are a couple of great bars where you can get good “McPub” (Scotland Yard) atmosphere and an incredible selection of craft beers on tap (Bier Markt).
Walk a block north to see the cool triangle building (there’s a cool fountain + statues there too)
My other recommendation for a nicer restaurant with unique location is the Keg Mansion, Jarvis and Wellesley. Regular Keg menu, food and service, and you can do it in a beautiful, big old mansion with unique atmosphere; or you can just go up to the bar on the second floor, and either get food or stick to drinks up there and was a higher class venue to meet up with new friends back in the day.
Sights
Casaloma - it’s an old castle, in the middle of the city (now), some rich guy built way back in the day, but it’s fun to explore and look around and as some nice views of the city as well. A few famous movie scenes have been filmed there as well.
Kensington Market - look it up on Google maps, it’s a small run of streets, nearby College and Spadina. Go there on a Saturday, it’s an eclectic mix of ethnic food (great Jamaican jerk, chicken places) some hippie style stuff, drug paraphernalia, and clothes, shops, and all kinds of fruits and other foods. Adjacent is old Chinatown, basically just walk south on Spadina, and remember that for after last call because some of those Chinese food places serve “cold tea” (beer served in tea containers after hours) . My go to for after bar food wasn’t the street vendors, it was the BBQ duck.
Was mentioned briefly a couple times, but you have to Walk Queen St., West if you’re younger and out about the town at night. Ending up at the Horseshoe Tavern for lively sights, and sounds, and they always have live music going there… People from all walks of life go to the horseshoe Tavern, and occasionally someone from a well-known band will walk in there you never know.
CN Tower is one of those places you have to see if you’ve never been to Toronto or never seen it… But make goddamn sure you go there on a clear day. Otherwise, it’s a waste of money, and then make sure you do all the fun stuff you don’t have to pay extra for, specifically walking over the glass, looking down thousands of feet, and then, having fun taking a running jump to land on there, while people jump off and scatter like cockroaches
Never plan to eat there, the food is extremely expensive over priced and not worth it. Life is too short to waste time on over priced food just to be in a revolving restaurant.
