well, it's really hard to say which is the best. One thing you can look at is the timings, the lower the better. But usually low timings tend to increase the price a lot which is quite stupid since timings don't make a huge difference.
No one will probably be able to tell you which is the best but I'm sure almost anyone will tell you to get your ram from a reliable brand. For example OCZ, Kingston, Corsair etc. There are quite a lot of good brands out there.
If you need more help then just tell us your price range and we will try to find something that looks good.
TBH, I actually think it's quite pointless getting 1066MHz RAM, because to get 2GB from a good brand, it's going to set you back about Â£100. And you cannot run PC28500 RAM with a 1:1 ratio unless you a really really high FSB. Think about it, you can buy a 2GB set of PC2 6400 CL4 (nice low latency) from Corsair , which is what I have, and run it in a 1:1 ratio (a 1:1 ratio is always ideal if possible) Oh and if you really have to have it at 1066MHz, the corsair 800MHz memory will overclock that far anyway. 2GB of this stuff costs Â£40 so you can get as much as your Mobo can hold for your budget. Anyone agree with me?
yeah usually I recommend people to buy ddr2 800 ram.
But if he wants 1066mhz then that's fine too, it's his money. It does give a performance boost. If that increased performance is worth the money.. well I can't answer that since it's all about personal preference.