We loved La Sirene and keep saying we want to go back, the petite train into town was an experience unto itself!!
Since we went there we have also discovered several other lovely sites. Castil Montrgi in Costa Brava is lovely. We went in October last year and had a great time. The campsite is great, the big pool was never busy (plenty of sunloungers available) the evening entertainment was bril and it was only a 10min walk to the lovely beach. We went for 10 days and found plenty to do. We stayed with Go For Spain but keycamp, siblu, etc have caravans on there too.
If you ever want to go nearer to disneyland i can highly recommend La Croix Du Vieux Pont. It is a great place to stay, disneyland and parc asterix are both within a 40min drive away, there is a large lake with pedaloes, ducks etc on there, amusements for all and it even has its own man made beach located in the middle. The indoor pool complex is great too.
For somewhere different i would recommend Duirnell, Holland its a theme park, waterpark, holiday park all in one with a beach nearby and amsterdam an hour away. We have just come back from there and had an amazing time. That was with Keycamp
Next October we are going to Salou, spain near Port Avetura and again staying with keycamp. I cant remember the name of the site (its on the keycamp website) but i have heard that it is really good there too.