I think I remember a McDonalds on the same side of the strip and between Planet Hollywood and MGM. Been there a few times.
I think my favorite burger was at the Mirage.
My first stay in Las Vegas was at the Mirage and it was a memorable one too. Got a lot of pictures with the wife and their botonical garden.
I'm pretty sure I had a burger at the First Food and Bar in the Palazzo, too.
I'm a burger man and love my hamburgers (and tacos too

).