Sushi Kaji on The Queensway and Hashimoto on Dixie Road are the only two places in town which offer genuinely top grade sushi. They are both just ****ing amazing, and are priced accordingly. Sublime.
A tier down, but still excellent are Hiro on King, Edo on Eglinton, Tempo on College, and Blowfish on King.
Sono at Yonge & Eg is surprisingly good, too.
Japango on Elizabeth is an odd one - I've had meals here that were astoundingly good for the low prices, but I've been disappointed, too. Maybe the single best value in the city when it's on, but too inconsistent to recommend. Avoid the location in the Beach, which doesn't actually seem to be affiliated with the one on Elizabeth. There's also a place in the Beach called Yumei that's pretty good, serving perhaps the largest pieces of fish I've seen anywhere in town.
All the places in the Annex are average, unfortunately, with Sushi on Bloor being a bit better than the others. The reputation and popularity of this place is inexplicable - way beyond the actual quality to be found inside. That's not to say it's 'bad' or anything, because it's certainly not - it's just not great, either (I'm referring only to the food itself).
General tip: in Toronto, go for salmon instead of toro - for some reason it's usually much better, especially in the cheaper places. Also, the following is perhaps more true wrt sushi than with any other kind of food in existence: nineteen times out of twenty, you get what you pay for. Truly good cheap sushi places are extremely, extremely, extremely rare.