Biggest value for the Dollar?

I khow from reading threads here that many people have bought part of, if not their whole system here. Many have scored some great deals.
In your opinion what was the best deal you got here for the money you spent?
Has anything you bought really exceeded your expectations?
Have you bought anything for full retail and still considered it to be an incredible buy???
I did not buy it here on audiogon, but I do see them here used, and did get the advice here. Passive volume control has been the best value for dollar in my system, biggest bang for buck and I paid almost full price.
Pass Labs X600 Reference Monoblocks. Paid less than one-third of the price.

A few years ago, I picked up a pair of NBS Monitor I speaker cables in an mid-week auction. They had no reserve, and I was the only bidder. The seller was very disappointed that no one else bid, but he kept his word and I got them for "next to nothing."
My JTM speakers with the full range Jordan's give me the some of the best sound I have ever heard for $1500. Unbelievable !
Not a component, but cryoed Hubbell outlets have been the biggest bang for the buck I've ever experienced.
DIY power cord made from Belden 83802 wire. For the $ (40) spent by far brought the greatest improvement to my int. amp.
The best deal and exeeding expectations: A pair of Jadis 200 mono amps bought last winter.
Full retail: A pair of Maggie bass panels bought in the late 70s, early eighties, still driven today with a pair of Krell 300 monos,(Audiogon, also exeeding expectations in this configuration) a Mark Levinson the man X-over and a pair of KBL pres in mono configuraton.(Also Audiogon, but as expected ) Blend wonderfully with the Quads and Sound Labs.
The best deal on a component from a price to value standpoint is the CAT SL-1 pre-amp I purchased used on this site. It is just superb and was only a few hundred more than what I sold it's replacement for. The improvement was dramatic.