I've seen them on the intercooler itself, on the "hot side" pipe and on the "cold side" pipe. Is there any "best place" to put it?

 

I like to see it as close to the TB as possible.

 

I like to have it placed about 6 - 8" away from the Throttle Body, for visual and functional purposes...

At that distance, it's noticeable and does not look like it's cramping the space of anything else, plus you dont have a huge vac line running all over. I guess the only way I know to describe it's function there is that when the butterfly closes up (at least on a Fuel Injected vehicle) it creates a pulse of air. I'm sure I've read somewhere that if it's too close to the TB that some of the pulse's air gets past the BOV, and too far away from it the pulse of air fades a bit anyway... I'm just offering an opinion of course, and cant VERIFY my statement since I dont have the magazine in front of me - I just seem to remember reading that not too long ago.