I may be cheating a little on this choice since there are two dolls, but Poetic Beauty Lilith and Eden Blair were packaged together in a giftset. This sculpt has a very strange history. There is supposed to be two separate characters with the exact same sculpt who are twins - the dark haired doll is supposed to be Lilith and the blonde is supposed to be Eden (but their hair colors change often). This sculpt has also been used with NuFantasy where Lilith becomes Kumi and Eden is Yuri. Examples (all individually packaged):
2008 Red Riding Hood Yuri/Eden
2008 The Wolf Kumi/Lilith
2009 Snow White Kumi/Eden
2009 Red Rose Yuri/Lilith
The Twins giftsets also started in 2008 with Elements of Surprise at The Heist Convention. Then Wild At Heart in 2010 at The Dark Romance Convention (I actually passed this giftset at retail price - stupid, stupid, stupid!). We got Lead Singles in 2012, Never Ordinary in 2015, and Poetic Beauty in 2017. Although they were sold separately, the 2016 Reckless girls wore almost identical versions of the same ensemble in different colors and had mirrored hairstyles.
In addition to the giftsets, the sculpt has appeared as individuals twelve times (if you count the reckless girls separately). Eden has appeared as a redhead twice (2009 Style Mantra and 2016 Trouble) and a brunette twice (2015 Wouldn't It Be Lovely and 2017 Changing Winds). Lilith has appeared as a blonde three times (2010 Great Pretender, 2015 High Frequency, and 2016 Smoke & Mirrors). It's very difficult to keep up with these girls!
Poetic Beauty was purchased through a W Club lottery, which I was fortunate to win the chance to purchase at retail cost. Here the girls are NRFB.