I couldn't agree more with Arinn's review calling The Unicorn "a solid standby."
You can never really go wrong with the underground pub but it will never blow your socks off. I will say for a pub with no windows or any form of daylight, you never really feel like you are sitting in a basement. The dark wood, bright tvs and usually nice staff trick your mind into thinking that maybe you are actually somewhere else. I don't know how they do it, but it seems to work.
I used to visit this place a lot more when I worked downtown. It is a great place for friends to meet because everyone knows where it is and again, they know what they are getting.
Now that I don't frequent DT as much, when I do end up on Stephen Ave, I tend to forget about the Unicorn. Maybe it's because I tend to enjoy staying above ground.