The Best Ever BGT Performance?

To mark the tenth anniversary of Britian's Got Talent, the series brought back some memorable faces from previous seasons. Is this the best ever performance in BGT History? People who were included are Jamie Raven, Attraction, Diversity, Kieran Gaffney, Ashleigh and Pudsey, George Sampson, Jon Clegg, Stavros Flatley, Old Men Grooving, Collabro and Spellbound.