I love Glenelg but sometimes can be to 'touristy'. For those who are new to Adelaide try the beaches north and south of Glenelg.
Brighton/Henley are two of my favs.
If you just want a scenic view and the possibility of seeing sealions/dolphins then there is always Hallett Cove. All you lucky people who have huge houses on the shoreline and beachfront...I hate you! LOL! :p