It seems like LTHers are serious about their sushi, so I'm going to share the place where most Japanese expats consider the best sushi in Chicagoland. As many of you know, the Japanese expat community isn't in the city, but in the northwest suburbs. So it makes sense that best stuff is in the suburbs.
My family has been going to Chef Sakuma for the best sushi in the area for as long as I can remember. If you are a White Sox fan, Tadahito Iguchi is a regular there as well -- my parents said they saw him on Sunday after the season opener.
If you like non-sushi items and you're willing to splurge, sit at the sushi counter in front of Chef Sakuma and order his Omakase (chef's choice) course. There are three grades, and they reflect three price points -- I believe it's $40, $50 and $60 (per person). You'll get several courses, usually with sashimi, a cooked dish or two, a soup (the dobin-mushi, when in season, is amazing), sushi and dessert. [sidenote: I am a bit uncomfortable with the "secret" menus that ethnic restaurants have. I've often noticed non-Japanese people staring at our food and opening the menu trying to figure out what the beautiful dishes that appear in front of us are. I am happy to explain the omakase course to them, but I feel weird about the discrimination and exclusion this practice implies.] We always have the omakase so I haven't seen the menu in forever, but they also have the typical stuff any Japanese restaurant would have. He also has a good selection of sake, so if you like the good stuff, ask for recommendations. His best customers often bring back rare bottles from various regions in Japan as gifts, and the chef sometimes lets the customers at the counter try them.
Unfortunately, Chef Sakuma's English is pretty poor and he's not all that friendly, but his wife is very approachable and talkative. Chef Sakuma has special soy sauce (I believe his makes it himself) for sashimi and sushi and pays a great deal of attention to every detail. Sakuma is the only place that I have liked the uni (sea urchin), so please give it a try and let me know if you think it's different than other places you've tried. For hamachi lovers, ask the chef if he has "kampachi" (a special kind of yellowtail) that day. That is by far my favorite, but I have never found it in the city. I find oo-toro to be too fatty, but his chu-toro is to die for. Chef Sakuma also marinates some items in wine (I think tuna and ikura) which gives it an unusual and delicious taste.
Sakuma's Japanese Restaurant/Sushi Bar
43 S. Sutton Road
Streamwood, IL 60107
(630) 483-0289