i think in the shows ive heard living on a prayer(electric) ousted the other tracks...mostly cos it was my first concert, and i was so worried they wouldnt play it cos they hadnt all night! but then the song came on, and i managed to find my mates there too, and we all got together to rock for one more song

but also, i think it gives a better feeling going away from the concert then a slow song...IMO