Fave Five

Monochromatic:  This blog Lifehacker is monochromatic, and one of technorati's top 100 - so it does quite well.  

This is a nice analogous color scheme and seems popular right now - green and blue.

Here is a good example of using a complimentary color scheme:  Plantilla-blogy-columnas.  It is using orange and blue.

Bright and pretty saturated colors in the flowers found here and called Colibri.

And last, probably my favorite look, the unsaturated colors.  Dark Ritual.