As I understand it: The silver/blue (cyannine) discs are the best if your primary concern is compatibility with older drives and stand alone players. Taiyo Yuden are probably the best of those. The phthalocyanine discs are almost as compatible (they won't work in 1x and 2x CDRW drives) but they're expected to last longer. Mitsui are probably the best of those. It's debatable whether gold is better than silver but since gold is more stable you could ere on the side of caution and use the gold discs if you're planning on keeping the data for a long time, however again you'll be sacrificing some compatibility and paying more.
I've been getting my discs at [url]www.cdrplanet.com[/url], they have both the Taiyo Yuden and the Mitsui, gold and silver, their prices are pretty good and they ship fast.