I hope you enjoy your trip to the Argos game. The Riders always have lots of fans show up, so it's guaranteed to be a packed house. Make sure to secure your tickets well in advance, they will be hard to get closer to gameday.
The best way to get tickets is to call area code (416)341-ARGO and speak with a ticket representative.
I can personally recommend seats between the 40 yard lines in either the 100 or 200 level. Do not go closer than the 15th row of the 100 level. My seats are in section 131 in the 33rd row, and I think they are excellent seats. Here is a virtual tour, click on any section in order to see the view:
These are the more expensive seats, but if you're coming from out of town, it will certainly be worth it.
For the two hours before the game, just south of the stadium on Bremner Blvd, the Argos throw the Bremner Street Fest, which is sort of like tailgating except you have to buy the beer and food off of vendors. It's nice, but don't feel too bad if you can't make it.
After the game, I recommend you proceed to Front Street on the north side of the stadium and walk east. On the north side of the street, just before University Ave., you'll see a restaurant called "Jack Astor's", which holds the official Toronto Argonauts After Party in their bar area. Many of the players and cheerleaders show up after the game, and they are very friendly and open to chat, take pictures, or share a toast. Make sure to hurry to Jack Astor's immediately after the game, since it fills up quickly.
I hope it's a great game and you enjoy the trip!