Gaming Ram

What kind RAM i should use for gaming computer?
i know there is like 2gb ram 4gb but what are the difference is ddram? or sdram? not sure if thats rite. And tell me which company ram is good for gaming computer? ex. corsair?
tell me all in deatails thx
Corsair is good, so is Kingston.
The generic brands suck, but are useable.
The thing to check for is Mhz, you need to match that to the speed of your processor, or you will be underpowering or trying to overpower it.
If you are replacing the RAM in your current machine, just look at the old card and see if it is on there, it should be and it is the easiest way to tell what type you have.
If you are asking which is best in a new application, go with 1-2g of DDR2 RAM with your virtual memory set at 4000 on both your upper and lower numbers.
Gaming PC Build. Part 4: RAM