NYC
Pataki can handle a crisis, not confidant about Bloomberg but Rudy's management of that city I doubt has been completely removed in the time Bloomberg has held office so they'd probably survive as they did 9-11.
New Haven
Newark
Philadelphia
Detroit
Chicago
Denver
The other cities I'm not too sure of. Detriot and Philadelphia strike me as real problem areas. Daley has his problems, but I believe he's rise to the occasion in Chicago. But the Illinois government at the highest state levels is massively of concern to me. This is the state of Durbin (D) and Ryan (R) and neither strike me as reassuring of Reps or Dems competancy in that state.