First I'd just like to say that none of the meat on a turkey is considered red meat. It's just white and dark.
As for your question, if you want to know which is better for you, then it's white meat (because it's leaner). If you want to know which has more flavor, it's dark meat, hands down (and it's also where all the juices are).
If you want to know what your guests would prefer, I'd bet it would be a variety. In my house, it's about half and half. Though it could be that your guests prefer white (it's not uncommon). To be safe, I would offer both, but perhaps more white.
BTW, I watched a show once that showed the evolution of the Thanksgiving Turkey. It's incredible how we got the turkey we have today. They have such an abundance of breast meat (which is the white) that they have trouble walking, and often fall forward during their attempts of getting around. They can't even breed naturally because of their giant...well, um, breasts LOL So the breeding is all by insemination.
Anyway, as a result, our turkey may be larger and offer more white meat than our grandmothers', but they're also much drier. The dark meat is where all the fats and flavorful juices are. That's also why it's so important to baste while baking. You want to get some of the juices coming off the dark meat onto the white meat so that it's not unbearably dry.