The truth is that you have your good brands, and some are better than others and then the largest part is just preferrence. Everyone here has different companies that they swear by. I am just going to break it down for you so you can decide by yourself. You have PC2100, PC2400, and PC2700. Now a lot of RAM that is rated at 2400 and 2700 is still 2100 but it is better and is clocked up. Now that the new industry standard supports PC2700 now, you will start to see companies producing real PC2700. And PC2700 is the fastest and would be considered the best. So if you want the "best" DDR RAM then buy PC2700, but only from a company that you have researched and one that offers a lifetime warrenty is always a good thing.