Probably my most used Rouge G by Guerlain is this one, 60 'Gabrielle'. For me it's the perfect nude, a peach-pink with lots of gold shimmer. It's super pretty yet natural and works brilliantly with a smokey eye. As it's also one of the Rouge G range I find it nicely hydrating and so I can get away with not bringing any balm out with me (which is just as well as this lipstick weighs a ton!).
Gabrielle Rouge G (flash)
Guerlain Gabrielle Rouge G (daylight)I bought mine from selfridges.com