Reds / Greens are really overused, its true, but blue ones just look like the mutts, especially whe you get a superbright one that you can use like a mini torch. They are also bringing out white ones now - could be smart as well, but i think the blue ones take the crown.
I like blue LED's, it's my favorite color. Though they use about five volts and in applications such as console modding they can suck juice up if you use a lot with limited amounts of power availble . In other words, red ones use about 1.5 or 3, I can't remember but it's one of the two.