I don't count... but I've not finished them as many times as you 2 seem to have... :sweatdrop
I always do it this way: First... I complete the game the normal way and often I get all the best weapons, armours and stuff and I always beat the optional bosses if there are any.
Then... I MAY play it the normal way once more depending on if I really got all the good stuff. If I didn't... then I play it normaly again. But if I did... then I don't play it the normal way again...
Then... I complete it in a "challanging" way...
And after all this I may play it in another challanging way OR the normal way... if I feel like it.