Well you should go north of the island these are some
Mellieha Bay
Golden Bay (Also you can view a web cam of the beach) I cant snd you the link as I am a new member but if you google it you should find it. There is also a site that collected most of the maltese web cams I beleive.
Paradise Bay
Riviera Bay
Gnejna Bay
Armier Bay
These are all nice beaches
Michele