Guu is awesome. I have been to the location on Bloor in Toronto a few times and Guu with Garlic in Vancouver, and I have never been disappointed.
It is a fun, lively atmosphere with staff yelling to each other and the food is fantastic. Between the selection of deep fried dishes to the lovely sushi options, you really cannot go wrong.
Last time we went it was my friend's birthday and they came out and sang the funniest, loudest birthday song you have ever heard.
The only downside can be the noise. The place gets packed and it can get very loud, especially if you are sitting in the front room with the low ceiling.
If you can handle the noise I definitely recommend this place for a fun time.