We have been staying at Lake Annecy for the last 20 years. At first, we would camp but by chance we came across Residence De La Plage, whilst out cycling. It combines modern comfort and quiet whilst being right next to the best beach on the lake. My children are now teenagers which makes it harder to find a holiday that everyone enjoys. The diving platform on the beach is there favaourite hang out, as they can catch up with friends and do all sorts of dives 3m and 5m boards. The local french children are very friendly ( and I have to say I have never seen such amazing diving, presumably because they have grown up with the board there all their lives ). We also have a small boat which we take out by joining the local sailing club ; you can launch there and the kids have learned to sail with their supervised lessons.
For younger children, the sandy beach is both safe, shaded and has plenty to climbing equipment, a paddling pool and a life guard.
My wife and I also like to go for October and May breaks when the lake is quieter. The autumn colours are lovely, as there are so many different trees, including birch, oak, maple, beech. In May, the lake turns a lovely turquoise colour as the snow melts.
Winter is our ski holiday; incredibly good value as Col de Leschaux ski resort is only 11km drive, cost 17 euro per day and less for children. You can buy one day or just pay per hour. The resort is lovely with loads of runs for all abilities. If you ski down the other side of the mountain you get to Semnoz.