Has there been any inexpensive item that enhanced your system's sound?


For me it was an inexpensive power cord that was laying around for years, a Pangea AC9.  I have it connected to my Yamaha A S2000.  I've tried the stock cord on the Yamaha and then some of my other cords, (Wireworld, VH Flavor 4, Acronlink/Oyaide custom cord and a MAC). I've had lots of amps and integrated amps over the years, and this is the first time the Pangea contributed to making better sound. It surprised me because I had tossed it aside and forgot about it.  Power cord performance is such a crap-shoot and dependent on so many other variables in the audio chain.  Any inexpensive item you've come across that enhanced your system's sound? 
foster_9
Yeah...would like some feedback too. For me...enhanced would be richer, fuller, smoother and unetched. 
The Pangea is a good one, and now the SE series starts at $50 and is a major upgrade in performance.
The tweak that transformed my system is the Synergistic Reseearch Red fuse. I haven't tried the Black fuse yet since I'm so pleased with the current results.

Placing a wood board under my preamp to decouple it from the rack was a cheap tweak that provided much improved sonics.
Almost forgot... Porter Port.  I added a Porter Port, and replaced a rather well known one.  The sound improved.