I have not used many elementals, I have one in the King’s castle in my 1st edition game, and that is mostly it. However in my 4th edition game I am working on something that I think will be fun. A cross of the air and fire elementals.
And thus will become my favorite elemental. I am hoping to use this new monster as soon as the players in my play by post game, are done with that House of Knowledge. There you have it my favorite elemental.