Zilart, Promathia, Lady Lilith, and The Shadowlord.
Bio Break
Much of the music. XI's OST has actually broken out of XI's circles somewhat.
Shantotto, as much as it chagrins me.
Burning Circles
The FFXI Crab
For weaponskill names hmmm... I'd say most all of the Empyrean weaponskills haven't had their names co-opted by XIV yet. Though one notable exception being DRG's. Though instead of Camlann's Torment they changed it to Coerthan Torment, so I suppose that keeps Camlann's firmly XI only (and shame on XIV for getting rid of the King Arthur reference. I bet it was Localizers striking again).
Bastok has a bigger level of infamy than the other two city states imo. But all three are fairly iconic to XI.