If your motherboard offers only very limited memory voltage options, then you will have to consider this memory from OCZ. Going from the stock of DDR2-525 to an overclock of DDR2-720 without any voltage increase is very impressive. On top of that you can tighten the timings some without a considerable loss of overclocking. If you know you won't need such high memory clocks, but prefer to have better latencies, you can also use timings of 3-3-2-4 which are very close to the limits of what most chipsets let you use. At this setting there is still enough headroom left for some overclocking.
Enthusiasts who want to pump a lot of voltage through their memory might not like this memory much, because it does not scale with voltage at all. Also relaxing the timings to further increase the overclock is not possible, but the overclocking range at the default voltage should be fine for most users anyway. Everybody should be able to run the memory dividers set to "faster than FSB", which gives an added performance boost.
On top of the solid performance you have OCZ's lifetime warranty and the unique looking XTC heatspreaders. All this comes at a very competitive price which will make you think twice about getting no-name memory for your DDR2 system.