One of the most exciting things about Alison DiLaurentis (Sasha Pieterse) being alive on Pretty Little Liars is that we'll get to see her come face-to-face with the Liars, who have all changed so much since they were four friends cowering under Ali's reign of capricious love and snark.

We're sure that Ali will quickly find that she doesn't have the same easy influence over the four Liars that she used to enjoy. But which girl has evolved the most since the old days? We've examined how each girl has grown, and then we want you to weigh in on who you think has developed the most!

Aria: Aria's still a romantic, but these days she's smarter and more independent that she was under Ali's thumb. Ali used to be able to push her around and even trick her, but we doubt she'll be able to get away with that anymore.

Emily: Emily is definitely one of the most changed Liars. From a meek girl quietly in love with Ali but in denial of her sexulity, she's become a strong, confident young lady who is sure of who she is and isn't afraid to face anything — whether it's coming out, or tracking down "A".

Hanna: Hanna has also grown by leaps and bounds. Once an overweight teen, completely desperate for affection and struggling with an eating disorder, she transformed herself into a queen bee with a mean streak after Ali's disappearance. She's moved on from that image, too, settling in as an outspoken, loving friend who might not always be the brightest bulb, but never lacks in braveness and passion.

Spencer: Spencer was always the Liar most willing to stand up to Ali, and over the years she's only become more sure of herself. She's learned to let down her hair and create her own goals — she's as smart and ambitious as always, but these days she no longer defines herself solely as a Hastings who has to act in a certain way just because of her family name. Plus, she's turned from just the Liar most willing to fight into a true warrior, ready to battle "A" no matter what.

Which Liar do you think has changed the most? Vote in our poll, and sound off in the comments below.

Catch the Pretty Little Liars Season 4 winter premiere on Tuesday, January 7, 2013 at 8 p.m. ET on ABC Family.

Rebecca Martin is an Associate Editor at Wetpaint Entertainment and our resident Game of Thrones, Breaking Bad, and genre TV expert. Follow her on Twitter and Google+!