These are the ones I could think of (in no particular order)
  1. "Across the Universe" by Fiona Apple
  2. "Across the Universe" by Rufus Wainwright
  3. "I'm Gonna Be (500 Miles)" by Sleeping At Last
  4. "Romeo and Juliet" by The Killers
  5. "Sally's Song" by Fiona Apple
  6. "This is Halloween" by Marilyn Manson
  7. "Total Eclipse of the Heart" by Sleeping At Last
  8. "Out of the Woods" by Ryan Adams
  9. "Once Upon a Dream" by Lana Del Rey
  10. "Ladder Song" by Lorde
  11. "Hallelujah" by Jeff Buckley
  12. "Pure Imagination" by Fiona Apple (she does good covers)
  13. "Chasing Cars" by Sleeping At Last (same here)
  14. "Wild Heart" by Futurebirds
  15. "My Man" Lea Michele
  16. "The Summer" by Natalie Imbruglia
  17. "Such Great Heights" by Iron & Wine
  18. "Float On" by Goldspot
  19. "Smile Like You Mean It" by Tally Hall
  20. "Hello Sunshine" by Syd Matters
  21. "All I Could Do Was Cry" by Beyoncé
  22. "Goodbye in His Eyes" by Natalie Imbruglia
  23. "Whole of the Moon" by Mandy Moore
  24. "Champagne Supernova" by matt pond PA
  25. "Friday I'm in Love" by Yo La Tengo
  26. "Sea of Love" by Cat Power
  27. "Chelsea Hotel No. 2" by Lana Del Rey
  28. "The Suburbs" by Mr. Little Jeans
  29. "This Charming Man" by Death Cab For Cutie
  30. I'm sure there are more