Skadden, Latham, etc. are second tier firms. First tier (New York) is Cravath, Davis Polk, Sullivan & Cromwell, etc. Boston Ropes and Gray, Hale and Dorr. Etc.
I don't want to get into a lame argument about firm prestige, especially on a style board, but on a national level Williams & Connolly & Latham & Watkins are more prestigious than Ropes, Hale, and probably Davis Polk. Â As for Clifford Chance, I believe most of its US offices were obtained through its merger with Rogers & Wells, which was a third-tier firm at best.