the best omakase i've had was at morimoto in philadelphia where the man himself created a 9 course dinner at the counter right in front of us. it cost us $150/head and much more in sake but the menu included abalone, fois grois, lobster, a huge block of seared toro, kobe beef, and just about everything that is considered expensive cuisine. i hear he's opening up a morimoto2 in the new aol/tw bldg so that might be a special occasion dinner for you and a lucky partner in the coming months.
as for now i can recommend sugiyama if you want cooked dishes as it is a kaiseki restaurant. for jsut sushi if you haven't tried sushi of gari then it is a must. make sure you make a resv at the sushi bar and order the "off-the-menu" omakase. it'll run you $100 but mr gari himself prepares the meal for you and what a difference he makes. i think he has a special fridge where he keeps all the best fish and only he's allowed to use. make sure you go before 9pm and do NOT use any soy sauce or wasabi as i'm sure he'll remind you while holding his big knife (the sushi is already seasoned to taste). also instead of using chopsticks using your hand to eat will impress the sushi chefs as being knowledgeable about their art. and "oishi" means delicious in japanese so giving him that compliment always brings a smile to their faces. i am not japanes myself so any effort i make to speak japanese is greatly appreciated by them. "arigato" means thank you by the way.
after gari, if you can afford it, kuruma or yasuda is the next you should visit. but be careful... these places can run you anywhere b/w $200-$400/head jsut in sushi depending on how much you eat. being as adventurous and big bellied as i am i ususally get into big trouble... jewel bako is mentioned often here in chowhound but although their fish is fresh and the sushi chef is very skilled the service is sooooooo slow i am always ill-content after the meal. i like to ejoy my meals with good company and conversation but 2 hours tops. both of my meals at jewel bako were over 3 hours with loooong waits between courses. some people enjoy that but not me so beware...
anyway, i hope the above has been helpful and enjoy!