Picking between affordable hotels

For when we are staying, I am mulling between:

* MGM Grand $150

* Excalibur $134

* Park Inn $95 - edit, i gather this is not a good loc

* Luxor $121

Are they all much of a muchness? All based on the strip. Currently booked in at MGM but it is refundable. This is a weekend with friends, lacking major The Hangover ambitions.