I did some searches, and saw that most of the omakase rankings were from a long while ago. My understanding is that Mori has moved on, so wonder if things have changed.
I have been to Sasabune, Mori, Sushi Zo and enjoyed them all. I found Zo to be the best of the three in quality and selection. Sasabune was fun but slightly below in quality. Mori was a bit disappointing to me but very zen.
I'm assuming Urasawa would be too expensive (i.e., willing to pay about $300 per person, but not more).
Anyway, Asanebo is on my radar screen as is Kiriko (a Japanese chef friend from Dallas, Yutaka recommended). Are these worthy competitors if I'm in town for only a couple nights?
BTW--I like more traditional omakase, i.e., nigiri served one piece at a time. I occasionally enjoy a cooked dish too if it's like hamachi jaw or something very delectable.