I find it pointless to say that imaginary numbers are less real then "ordinary" numbers. They're not, they just got an unfortunate name. No numbers can "exist" any more than imaginary numbers in any sense, since all numbers are pure abstractions anyway. We're used to using numbers day by day, to describe amounts and stuff, but that doesn't make them more "real" than words. Besides, numbers such as (non-LMNO) Pi can't even be represented finitely with digits, are they real? Pi can be defined as the relation between the circumference and the diameter of a perfect circle; does such a thing "exist"?

The important thing to remember about science is that it's really all just about making models; pictures of "reality". If imaginary numbers are a cool way to make a working model, why not use them? Because some people find them hard to grasp?

But there is a difference between unreal and real numbers in the sense that real, positive numbers are observable. I can see that I have two apples in front of me; I don't see, for instance, that I have minus nine monkeys. Likewise, i, pi, infinity etc are conceptual rather than 'real'. Pi is a definite value, yes, but no-one can actually list all of it in any form other than a fraction - just the same as any other irrational number. i and infinity are very useful for mathematical working, and of course they have a very important place in maths and physics - but nevertheless, there is still a distinction between 'basic' numbers and these more advanced types.

Of course, 42 > Everything else.