Well, I would suggest you search the internet for reviews on the camera that you owned. Some sites like dpreview did memory cards tests using different brands. esp Sandisk III and Lexar 80x WA. So if your camera can benefit from the high speed and cost is not a problem. Get the one that is recommended. Also one thing to note is the firmware of the camera.
If you are owning a Canon DSLR, there is some compatibility problems with Lexar. So be warned. Check with the vendor when you make your purchase. No such problems with Nikon but not sure about the others.
Kingston, Lexar and Sandisk are all good. The only difference between these 3 and the rest is quality control. Afterall, a handfull of OEMs manufacture all teh world flash memory cards, and even fewer chip manufacturers produce the memory chips for everyone.
That said, did many tests, not scientific but who cares, with various makes, using various different cameras, I found the write speed differences are negligable. For example, after the buffer of my 20D is full, shooting raw, it takes an average of 1 to 1.5 second for each subsequent shot. In terms of speed, percentage wise, it's meaningful, in practice, I don't see it. Where I found meaningful difference in speed is when down loading to a PC or portable HDD.
I generally buys the cheapest among the big 3 card makers, and after 4 years and over 50K frames, nothing to complain, and still don't have a preference among the 3.