If I were looking for the absolute highest quality memory (without being able to test every kit on the market), I would look for these attributes...
* DDR2 rated at 1.8v or lower
* The lowest latency ratings (still holding to the 1.8v standard)
* The highest speed rating (still holding to the 1.8v standard)
Triangulate those parameters, then balance them with price and you have the best memory for the money.
You don't have to overvolt them. Usually, the higher voltage is needed for higher frequency or lower timings. If you don't need the higher freq or lower timings, then just use JEDEC standard voltage and timings.Just to reiterate the warning about voltage. I built several comps in a batch about 3 years ago, using 'overclocking' DDR2 6400 RAM which was 2.1 or 2.0 V from multiple manufacturers.
Fast forward 2 years - 5/6 sticks have burned out, and even a replacement pair of sticks have also failed.
I'm never buying 'overvolted' RAM again.