Basing a party on your kid's favorite tv program is an easy way to chose a theme. I know growing up Sesame Street was one of my favorites! (and smurfs and fraggles lol)
Sesame Street theme is so fun because you can really go crazy with colors, textures and shapes!
Start with a super cute invite - the iconic street sign is a perfect logo! Source
Awesome details.... colorful garland, characters in photo frames, character buckets - so clever! Source
On your dessert table continue all the pops of color - clever ideas: bins used not only right side up, but upside down too! Colorful labels on the lids of the snack jars! Source
heehee... her husband is such a great sport! LOVE the idea of an oscar the grouch trash can photo booth! major kudos! Source
Sesame Street cake pops would make a great favor and add lots of color to your table! Source and tutorial