I don't think there is one that is universally flattering. Finding the best red lipstick for you is, in my opinion, right up there with finding the best jeans.
And I have to disagree with kuriso, blue-red is great for brunettes with blue undertones, and many with golden undertones, but some people look much better in a warm, russet-toned red, for example, most fair skinned redheads will do better experimenting with those, but because there are so many variables, many very subtle, from skin tone to that rainbow of undertones, to eye and hair color and even bone structure (which will affect how light hits the lips) that trial and error, and a lot of it, is the only sure way to find YOUR red - and it may not be a "true" red at all!
The absolute best one I have found recently is a high-pigment gloss called Extreme Lustre or something, about $3 at Sally's, the shade called "Scarlet" is a beautiful blue-red, spectacular on brunettes with the blue and gold undertones, especially this one.