Patrician to the core, Hugh was firmly in the Top 100 until 1903. Now it's used very quietly, though the name is still in the Top 1000.
Hugh has always been particularly prevalent among the Irish -- there have been 20 Irish Saint Hughs, and it's traditionally associated with the O'Donnell clan. Hugh was an early immigrant to the New World, where there were two Hughs in the first English-speaking settlement in America. Hugh's biggest drawback is its sound, barely more than an exhaled breath. Actor Hugh Jackman adds a dash of the romantic hero, and other prominent Hughs include Hugh Laurie (born James Hugh), Hugh Grant and Hugh Dancy. Then there's Hugh Hefner, known to the world as Hef.
Hew and Huw are the distinctively -- probably too distinctively -- spelled Welsh forms.