you should stay well clear of cheap ram - sometimes it`s better to pay more, than having to pay more later becuase you bought a product which is of lesser quality!
you should try the system scanner at crucial.com that will analyze your system and tell you what the best type of ram is for your system
secondly, software like adia32 and everest <one of my personal favs - will tell you the perfect ram timings to get the best out of your whole system/cpu/motherboard
then you will know exactly what ram timings your motherboard can support then look for ram (best to be branded with warrenty) I know alot of companies are offering lifetime warrenties on ram also these days.
lastly
http://en.wikipedia.org/wiki/DDR_SDRAM
study this page, and other links from this page, it will give you a full understanding on how one stick of ram can differ from the next depending on how many CHIPS are actually on the stick of ram, 4 chip ram, 8 chip ram, 16 chip ram, double sided chipped ram also may not be compatible with certain motherboards. so you have to watch out for these things before you know which type of ram is best for your particular configuration. also watch out if your thinking of going dual channel mode (128bit access rates) if your going dual channel you really should use exactly the SAME type and brand of sticks, mixing them will only lead to problems, loss of data and possibly a really bad crash on your computer.
