Edit in JSFiddle

var PLAYLIST_ID = "PLq1Df5yPUOMtaZJsmL_TY5Y1xY12LI6GH";  // YouTube Playlist ID (privacy must be set to "Public")

// playlist URL; using jsonp content type because it's cross-domain
var PLAYLIST_URL = "http://gdata.youtube.com/feeds/api/playlists/" + PLAYLIST_ID + "?v=2&alt=json-in-script&callback=?";

// on document ready, call loadPlaylist()
$(function () { loadPlaylist(); });

function loadPlaylist() {
    $.getJSON(PLAYLIST_URL, function (plJSON) {                      // get the playlist feed
        for (var i = 0; i < plJSON.feed.entry.length; i++) {         // loop over video entries
            var tEntry = plJSON.feed.entry[i];

            // video properties
            var vURL = tEntry.media$group.media$content[0].url;
            var vTitle = tEntry.media$group.media$title.$t;
            var vDesc = tEntry.media$group.media$description.$t;

            // create title and description
            var vid = $("<h3>"+vTitle+"</h3>");
            if(vDesc) vid.after("<p><em>"+vDesc+"</em></p>");
            
            // add videos as iframes
            vid.after("<iframe width='100%' height='400' src='" + vURL + "'></iframe>");
            
            $("#playlist-container").append(vid);
        }
    });
}

<div id="playlist-container"></div>