A friend took some photos with her new camera, and somehow got the settings wrong for color, so I tried out some filters to see if I could get better colors. Here is my results...I think G'MiC is absolutely amazing as all I did was use some of the filters under colors, and voilà, lifelike colors with very little knowledge or work. The original is on the left, the color enhanced on the right. Also, I was wondering what is everyone's favorite method of making colors "pop".

Don't have any 1 actual method.
I usually use curves with hue/saturation - changing the saturation of each colour separately until I get what I want. Then contrast if needed.

2 Ton, I think you got a good improvement. Anyway, I tried this. Duplicated layer - desaturated - and Layer Mode. I tried to reduce the red tone.

very nice Isabella. I would now like to be able to make the colors more vibrant, but when I try, the skin gets too 'vibrant', also.

I like to use layer masks and the airbrush tool to get areas included or excluded from certain layer effects. That with a little gaussian blur can make for some nice soft transitions that look natural. Like if you are trying to enhance red, but not the skin color of your subjects.

Trying to improve it, 2-Ton. Thank you for your advice ek22. Let me know if it's a little better.