We just got back from P.J. O’Brien‘s for supper. Great place. The food was the best that I’ve ever had at an Irish pub. Beer and whiskey selection was good. Waitresses had Irish accents (no kilts). Just a great place. As BlogTO said, “…older crisply dressed Irish gentlemen almost always to be found sharing a story or a joke somewhere in the place, this is as Irish a pub as it gets. Period.” And, you know, I’d have to agree with him.
Check it out if you’re at Yonge and King (the pub is located one block south of King and two blocks east of Yonge).
As a side note, Him and Her are going to try to hit up each of the Irish pub’s in BlogTO’s list of “The Best Irish Pubs in Toronto.” So far we’ve been to 5, and He thinks it’s safe to say that Mr. O’Brien’s is the most authentic…well, except that having really good food might compromise it’s legitimacy as a REAL Irish pub!
hishersandtheirs 
Since you’re in downtown Toronto, try the other one Irish Embassy on Yonge & Wellington, Irish Embassy- that’s good.
Brazen Head in King West (Liberty Village), take the King streetcar from your Deloitte building.
Other not bad places: Flatiron & Firkin (a block east of Yonge & Front) and Fionn MacCool’s on Esplanade & Church.
Thanks for the comment, Ryan. I’ve been to every place you mentioned, except for Brazen Head. It’s definitely on my list though!
Irish Embassy is really neat. It’s in an old bank!
Flatiron is good too. Haven’t been in a while though.
And that Fionn MacCool’s is probably the best Fionn’s in Toronto. Much more lively than the one at Church (or Sherbourne?) and Bloor or at Yonge and St Clair. They’ve got the same pint Fridays deal as D’Arcy Magee’s on Sparks st in Ottawa.
Have you been to the Foggy Dew on King west? It’s pretty decent!