Funny that we were just discussing this.
My oldest DS said Flame Tree at AK (CS) and Crystal Palace (TS)
DH said 'Ohana (though he wasn't there for our last less-than-stellar meal there) and Biergarten
I said Jiko and Tusker House. (DH then said, "OH YEAH, you are right!") We used to like Boma but our love for those two places has meant we don't go there anymore!
And, DH and I agree that Captain Cook's is our favorite consistent CS.