I love both Radha and Rukmini a looooot, but ever since I was young I've always felt a strong connection to Rukmini Devi. Her character reminds of Devi Sita: pure, steadfast in her devotion, softhearted, undoubting, etc, and she never showed any bitterness towards any one of Shri Krishna's wives, and she was never insecure about her place in his life as well, unlike some of the other wives.
My favorite story with her is undoubtedly Shri Krishna Tulaabharam, she really proved herself to be the most devoted of all of Krishna's wives.
I generally do not make any Rukmini Devi sigs, because I don't really like the actress who played Rukmini in BRC's MB, and since I never saw many epis of Pinky as Rukmini in RS's SK (also cause I do not like seeing SDM as Krishna in the second half of SK, lol), I don't know the actress enough to be a dan. But I love the character of Rukmini.