Alpe d’Huez is one of those climbs you “have” to do but the Glandon/Croix de Fer from Allemont or Galibier from Valloire are miles nicer and more scenic. Don’t be tempted by climbing the Lautaret though as the tunnels on the way up are pretty sketchy.
Also, if you’re going up you Annecy via Leschaux, I’d head up from Leschaux to Semnoz as you’re missing an amazing climb by just doing the lake loop (the path is pretty boring in parts, stunning views though). The ride back through Faverges isn’t hugely inspiring either. If you have a car, I’d drive to Doussard and do a loop of the lake via Semnoz and the Forclaz.