Suspicious Minds, In the Ghetto & any of his gospel songs.
Side note , my mom's cousin was a member of the Jordanaires & sang backup for him & was in some of his movies. I went to the Rock & Roll hall of fame in March '09 & they had Elvis stuff including a payroll book & her cousin was in it. I thought that was pretty cool.
I find myself often quoting Elvis to my staff..."I need a little less conversation and a little more action please"...who knew it was a song about being productive at work?