Alright, i'll buckle on the great debate (somewhat). I do get what they are saying and I did say Apple is the best. I feel no ill will toward iMacs, they are a work of art and quite frankly in my opinion any Mac is better than a PC (thats another fight altogether) (for the PC users that was a joke).
No really either would treat you very well for quite some time, I think we all have weighed in on this so the real question is which model do you tend to gravitate to, that is the model that would be best for you.
Keep in mind, I would love to have a new 12 core Mac Pro fully loaded (ARGH,ARGH, ARGH) but my lowly old Machine in reality is working fantastic. Anything beats Crayons!