1. Bron y Aur Stomp Led Zeppelin
2. Blackbird Beatles
3. Moonlight Sonata Beethoven
4. Fugue in D Minor Bach (easier to play in E minor on guitar)
5. Crossroad Blues Robert Johnson
Granted it might take some time and effort to learn these (well not blackbird, and not really fugue in D minor) but they all sound really nice on acoustic guitar. Blackbird's a real crowd pleaser, and its easier as can be.