There's two ways to go here: Try to clear up the "stuffed" sound, by lessons, pills, exercises, operations and therapy...
Or... deal with the deck that God gave you, and play up on your individual uniqueness!
I always vote for the latter, every time. Who cares if you sound a little like Charlie Brown at the national spelling bee? Go for it! Be a character singer. Develop your own voice (not someone else's).
I'm tired of the 3,000 singers that all sound the same anymore. Boring! Forgettable.
Be Carol Channing. Be Zero Mostel. Be Bert Lahr. Hell, be Bernadette Peters with her raspy whiskey voice!
As far as material, that has more to do with your personality than your adenoids. Pick something you like that makes you think, "Hey, that's me!"
"Jaws is the Citizen Kane of movies."
blocked: logan2, Diamonds3, Hamilton22