Biggest "bang for the buck" audio gear you have owned(in your history)?

This is very subjective, and your opinion on your own systems/items is all that really counts.

From the beginning to now, these would fit that category for me: (in no order)

Original Large Advents
Dahlquist DQ-10
Conrad Johnson ART pre.
Original Monster interconnects and speaker wires.
Nakamichi SR-3a
AR Turntable
Audio Research LS-12
Magnepan 1.6
Magnepan 20
Wireworld Gold Eclipse III
Audio Technica Electret Condenser headphones 
Magnum Dynalab Etude and 108 tuners
Magnum Dynalab Receiver (original)
And in those "early days" special pressings and imported Jazz albums. 

There may be others I am forgetting, but these were very good items along my journey. 

Magneplaners, of course.

Love to see the large Advent's mentioned.  Mr. Kloss was a pretty smart guy--I mean, he invented the acoustic suspension speaker...where would be be today without that?  

Unfortunately, those speakers have been passed by in today's world, but KLH and Advent and the Videobeam are clearly major milestones in the industry and Mr. Kloss will always be remembered as the amazing pioneer he was.

Now, as for Jim Winey, well, he simply moved the bar so high that, thus far, no one has figured out how to move it higher.

Bloody hell man, It has all been best bang for the buck since day 1. 
  1. Began with JBL 4311's for 1/2 price in 1979, paired with an Onkyo TX 6500 and HK turntable with ortofon cart.  I conned a friend into transporting for me from Crazy Eddie's in NYC so I didn't have to pay for shipping. Crazy insane deal. But anyone who knows Eddie knows this prices are, well insane. That system progressed with the 4311's at the heart throughout and until till mid nighties' with the help of recycled audio in Boulder CO. Hands down the coolest place on earth for the budget college kid audio enthusiast. I remember getting my first credit card on Norlin Quad and heading there directly. Carver M500 and Apt Holman preamp for under $500. That was the limit on the card. Progress to 1997. Bought a highly modified set consisting of a pair of Infinity RF 1.5's a ridiculously modified Hafner DH-220 with 2 levels . Lower had over 80k uf Cap and a huge toroidal transformer and an early ps audio preamp with external power supply. $300.00. That system was built by a sound lab engineer from NL CT. Man if you are out there somewhere, I will forever be in your debt. I could go on and on. My current favorite system is dell windows app tidal precision laptop on battery> Peachtree nova pre> Adcom 555 (crown jewel of the system) DIY based on Blue Sky audio mods so graciously posted and some poaching from hoppe's brain parts list and all silver and copper inside > Dunlavy SM-1 and a modified Adcom GFA 5500 mono channel feeding a Dunlavy SC-S2 via active crossover - sorted. All for under $5k .  I have to say, I could be the master of audio nirvana on a budget. Anybody ? Cool mentions above, but come on guys - systems?
About 14 years ago +/- I bought a pair of McIntosh Mc501 mono block amps to drive my 3.6 Maggie’s.  The make the Maggie’s sing as they have the power and current to feed them what they need.  I bought them used, they are still in terrific condition and if I were to sell them (Not!), I could get what I paid all those years ago!

That IS getting your money’s worth out of a product!!