Right below the press box along the sidelines. The view is great, the fans are rowdy. I would avoid anything past row 20 just for the experience you'll get sitting that close to the field. You'll be paying big money to be there, you had might as well go all out and sit down close to the field.
Even though Ralph Wilson is kind of an eyesore, there is a lot of history here and it's one venue you can't leave off of your NFL stadium bucket list.