I'm a huge fan of Tropicana's lemonade, available in single-serving bottles in some depanneurs and other refrigerated drink displays. It comes in a rather distinctive bottle which is mysteriously absent from google images, but those of you familiar with Tropicana single-serving products can picture their orange juice bottle but with yellow product information and a lemon on it.
I don't recall what possessed me to try the Tropicana lemonade as I rarely buy bottled drinks and I find most commercially available lemonades sort of chemical and watery. Tropicana's lemonade is full of pulp and has a pleasant homemade kind of taste, complete with real sugar flavour rather than freaky sweetener aftertaste. I frankly can't get enough of it, but after a read of the nutritional info I've been limiting my intake to one a week. One little bottle is a sugar bomb and clocks in at 200 calories if I recall correctly. I also discovered the prominent pulp is in fact grapefruit pulp that has been added in after the fact, so those on medications that caution against grapefruit intake may want to abstain.
Still, this is by far the best readymade lemonade I've come across. For those of you interested, Minute Maid single-serving lemonade is by far the worst, with its neon-pink counterpart ranking a close second. (I suspect these may in fact taste the same but I do get a certain pleasure from drinking something pink.)