Where to use a pair of interconnects?

I have an interesting question that will cause some discussion I'm sure. If you have only one great pair of interconnects and the rest being average where would you put them in your system? Amp to preamp or cd player to preamp?
I have always used my best interconnects from preamp to amp.
where it sounds best

you will get many different answers but your ears are what count

I went against the norm (from source to pre) and preferred it you might as well
What Philjolet said.
Preamp to amp.
I second, what Philjolet said...
Philjolet hit it on the head. Its your ears - expectations, with your system in your home.
No two systems or listeners are the same.

Let your ears decide where the ICs provide the best performance boost in
your system.

In other words, go with Philjolet's recommendation.
Here's the logic:

If you only have one source, it seems that the best should be on the source. Once a signal is altered, it can't be fixed because the original information is changed and the next piece of equipment can't guess what it should be.

If you have more than one source, it seems like it should be on the preamp to amp so that all of your sources receive it's benefit.

Now here's the real world:

You need to go with Philjolet and just try them. It's your system, your ears and you know what you want or like.
I agree, where it sounds the best.
However in my three different systems, the interconnects sound the best between my preamp and amp.
I reject the question. I just went ahead and bought the other ICs I needed. ;-)

Seriously, though. I have been through this before to know that it doesn't really make that much difference if you are only upgrading one IC. If you let this drive you nuts, you will go through the same exercise each time you add another set of ICs. And it will be different each time. You really won't hear the full benefits until you get them all upgraded anyway.
I prefer my best IC going from sources (CD, DVD) to my pre/pro.
It depends on many different factors.

You just have to try it in different places, compare, and decide.

Currently my most expensive IC (Harmonic Technologies Truth Link)is between my DAC and Pre-amp because that is where it lends itself best with my current set-up. In the past, it has been used elsewhere.
You tell us - source/pre, pre/amp. Which sounds best? Can you even discern a difference?
One thing concrete to consider if you have multiple sources, ie CD and phono and maybe others, and your different ICs sound different to you, is the IC used between pre-amp and amp will affect the sound of all sources whereas if used between a source and pre-amp, it will only affect that source.