It depends on the players and their opponents knowledge about the particular opening played...

The one somebody just and they are not even winning more than their fair share of wins but are losing 60%+ of their games with it.

Caro-Kann: Panov-Botvinnik Attack

1. It's super-complicated.

2. It's super-complicated.

It depends on the Beginner.  I started out in 1996 with a good understanding of the Queen's Gambit, but most others can't handle such positional openings at the start.  For me, I had trouble with the Ruy Lopez.

And Chessteenager, it's "Beginners", NOT "Begginers".  You need to work on your spelling before worrying about non-important stuff like chess.

I agree with the comment by:"ThrillerFan".

The Parham is a pain for beginners until they learn how to handle it.

What about the Murphy opening for beginners?  

4 move checkmate.

When I started, I had a hard time whenever anyone didn't do e4 or prevented me from doing e5 if I played black, and I as white, I hated both e5 and c5 as black's second move.

The chase variation of the Alejhine as Black

The sicilian as white

what does any beginner like for the other person to play, other than what allows yourself to play any moves you want to?

Kings gambit as white. If they accept and dont know what todo afterwards the game can be over very quickly.

Easily the worst.