Oishii is by far the best all you can eat sushi I've found in Calgary thus far!
There are definitely times that it's a busy place - Friday and Saturday nights especially - and they don't take reservations for small groups, so plan your trip strategically! If you are willing to wait, Riverbend Station is a good local pub. But save lots of room for delicious sushi!!!
I've been here a handful of times and have never been disappointed. The little portions are just perfect - you can try a little of everything without feeling like you have to pack away huge portions of food. We definitely have our faves: California roll, spicy salmon or tuna roll, the mango roll and the little appies like the Thai spring roll, pork dumplings and the chicken teriyaki. Heck it's all good! Be sure to save room for ice cream with tempura bananas!
The service is great and the food comes out quickly. They don't keep you waiting around for more rounds of food either. We come every few weeks and will keep coming back for more!