So in the theme of education, I opted to expand this alphabet to include upper and lower case letters for more of an epic creation. Even with this, I had to put some popular characters aside, including Hoots the Owl, the Twiddlebugs, SAM the Robot, Sully, Biff, Barkley, Betty Lou and Baby Bear (that's a lot of B's). How many can you name?
Legend: Anything Muppet, Abby Cadabby, Big Bird, Bert, Cookie Monster, Gladys the Cow, Don Music, Dorothy, Ernie, Elmo, Forgetful Jones, Farley, Grover, Guy Smiley, Herry Monster, Honker, Ingrid, Invisible Man, Mr. Johnson, Joey Monkey, Harvey Kneeslapper, Kermit the Frog, Little Bird, Lefty the Salesman, Murray, Mumford the Magician, Dr. Nobel Price, Natasha, Oscar the Grouch, Ovejita, Placido Flamingo, Prairie Dawn, Queen Olivia, Queen of Six, Rosita, Roosevelt Franklin, Mr. Snuffleupagus (aka Snuffy), Sherlock Hemlock, Two-Headed Monster, Telly Monster, Uncle Jack, Umeko, Count von Count, Captain Vegetable, Wolfgang the Seal, Slimey the Worm, X (star of The X-Files), Ex-Ray, Yip, Yip, Zoe, "ZZ Blues" lead singer (from the band Over the Top)
Prints, skins and shirts are available at http://society6.com/mbaboon/Sesame-Street-Alphabet_Print or http://www.redbubble.com/people/mbaboon/works/9042639-sesame-street-alphabet. Society6 tends to have better pricing depending on your location, but Redbubble has more options (like kid-size shirts).