I love MAC lip liners! The one that I use the most would be Naked. The color is perfect to line my lips with and use any lipstick with. My second favorite and most used would be subculture.
I have been looking high and low for a lip liner that could neutralize my lips and finally found one! I have pretty pigmented lips as a natural colour and it's harder to find nude shades in lip products that are a "true nude". I find that conclear is a bit too harsh to use, it makes a "dead look". This lip pencil shade has just the right amount of pinky peach in the tone that it still gives warmth to your nude lips. This shade is also opaque enough to completely nude your lips not matter how much colour your natural lips have. This is a bit pricey for a lip liner, but it is great to use as a base and it makes brighter lip products pop. You do get a good amount of product for the price, but I highly recommend this lip pencil shade if you are looking for a true nude lip.