I really like Adèle. It's a beautiful-sounding and looking name. I think in the English-speaking world the accent is rather superfluous and would only create problems, but just aesthetically it makes this name look even more sophisticated. I think it's very feminine, international, ages well, and could be a really cool alternative to more popular names like Adeline and all its variations.
This was a common name among 10th-12th century queens and other nobles in present-day France, such as Adela of France (ca 1009-1079) (Latinized version of Adèle de France), mother-in-law of William the Conqueror through her daughter, Matilda of Flanders. Others include Adela/Adèle of Champagne (ca 1140-1206), third wife of King Louis VII, Adèle de Meaux (ca 934-984), wife of Geoffrey Greymantle, Adèle de Vermandois (bef 915-960), wife of Arnulf I of Flanders, and Adèle de Normandie (ca 1067-1137), daughter of William the Conqueror and Matilda of Flanders.