If your favorite part of this drama was the chemistry between Lee Sang Yoon and Lee Bo Young, then maybe check out another drama they did together. They're very different from each other, as one is a 50-episode family drama, while the other is a 16-episode political thriller. But if you're watching for the romance, then both shows can satisfy you in different ways.
Both dramas include lawyers who solve a crime that is close to home. In Defendant the victims were his wife and daughter whilst in Whisper the assailant is his new bride and her lover (so he his less inclined at the beginning to solve it). In both dramas they have a female helping them solve the crime. Both have similar feeling to them as well.