Hate to be forcing your hand there...
Well, I did just complete my second playthrough a couple of months ago, but playing SoTC again is hardly a punishment
I'll try it on hard.
My favourite colossi are number 9 (Geysers), number 14 (Breaking the Ruins) and number 15 (inside the ruined castle).
Number 13 was really aggravating, I thought. He took me forever. I hate getting onto him only to fall off due to my crappy R1 button.