Inspired by hearing Adele's Someone Like You this morning and realising that the the pre-chorus is easily my favourite bit - not as OTT as the chorus but more interesting than the verse. From 1:00 onwards in the vid:

http://www.youtube.com/watch?v=s_Zs7XS3XUo

Buddy Holly is the best example though, 2:20 here:

http://www.youtube.com/watch?v=kemivUKb4f4

What else you got?