Probably the best bring your own wine (BYOW) all you can eat (AYCE) sushi in town.
I love how they actually make the sushi per order, which can take some time though. Get ready for a 20min wait for your sushi. In the meantime, order the seaweed salad and soup they are really great.
I only write this review because many people seem to complain about the time it takes to get orders. If you want industrial AYCE, go to sushi st-denis or kanda, you can even order sushi by the piece there (never a good sign imho).
It's definitely not the best sushi in town, but it's an all you can eat. I find it coming second only to Ginza which is my #1! But Sushi 999 is just amazing for the value (bring your own wine!:) AND you get sashimi for lunch time aswell!!! Very few others do it (Kanda=crap, Sushi palace = decent).
But what I really love above all is how friendly they are. I don't like mayo, and they never complained about me asking to leave it out. They ever came back to me regarding a tempura something that may have some on it.
I would recommend this place to someone who's on a budget, wants pretty good sushi, likes sashimi (decent sized, fresh, and it seems more juicy than other AYCE), and especially if you want to bring your own wine! :)