Great question and excellent choices to begin with
WHen I was a young kid, I listened to my father's Elvis records. He only had two live albums: CBS The Concert ('77) and Elvis In Person ('69). I remember loving the intro of Johnny Be Good when after James' part, the bass would slide in, followed by the drums.
Another intro that always, ALWAYS pleases me is the one from Can't Help Falling In Love (live version): silence, fantastic pianopart, great piece of drumming and then Elvis falling in... the fact that it has been used more than 1000 times during his last 7 years should say enough about the quality of this song.
Third choice would be "Steamroller Blues": the intro has been changed slightly over the years, but it kept being a wonderfull, dirty, swampy intro with drums, piano, guitar and bass... fantastic
But browsing through my collection for this topic, it's funny to suddenly find out that Elvis' music has fantastic intro's. Just look at songs as Give Me The Right (or any other song from the Something For Everyone album) or That's Something You'll Never Forget (one of the most artistic, haunting intro's of an Elvissong).
P.S. Fantastic avatar you've got. Is that edited? It's a very and rare point of view.