Too sweet? Try making your own, less the addition of massive amounts of sugar. "Storebought" versions are always too sweet, catering to current tastes and becoming less sweet from the large amounts of booze added. There are even people who put white rum or vodka in eggnog. Cutting off their ears and slitting their noses form the appropriate punishment, so thatb you can recognize and avoid them in later encounters. Boubon, dark rum (Not "Navy") or brandy are the only appropriate additions. Most rye, Canadian blends, and Erse Poteen lack the sort of pervasive flavor needed, and most Scotch adds peaky smokiness which doesn't work. Personally, I like a couple of the Spanish brandies, darker and "richer" than Cognacs or Armagnacs.

...although I must admit that for me, eggnog is either a "dessert", almost free standing, but potentially better when supported by some of the fancy Christmas cookies (dreams of little gingerbread men topped with candied pecans or walnuts come to mind) or a piece of "real" fruitcake (dark, moist, aged with an infusion of spirits) or possibly a late evening snowy weather party drink, apres' ski or other outdoor event.