In regard to the previous educator's response to this question, I would argue that romantic love is one facet of the love that Janie is looking for.
When the novel begins, Janie's closest and most loving relationship is with her grandmother—the only family member with whom Janie has any contact in the novel, given that her mother became an alcoholic after surviving the trauma of being raped by a schoolteacher. However, her grandmother's fears of Janie being "ruined" hinder Janie from fully exploring her burgeoning sexuality. To quell those fears, her grandmother marries her off to Logan Killicks, an older farmer. Initially, Logan satisfies Janie's sexual curiosity; then, he stops "speaking in rhymes to her," meaning that he makes no effort to give her the affection and attention that she wants. She finds this instead with Joe Starks who makes her feel special by courting her. At this stage in her life, because Janie is too young to understand her needs fully, she believes that love is something that is projected onto her by a man.
She remains with Joe until middle age. As she develops more personally, she realizes that Joe isn't interested in her for who she is but for what she represents—a beautiful, light-skinned trophy, proof of his importance in the community in which she is a mayor. Both Janie's beauty and her proximity to whiteness turn her into a commodity. So, when she asserts herself, it offends Joe because he regards her as something to be seen but not heard.
It is only after Joe's death that Janie becomes free to exist on her own terms. Her relationship with Tea Cake is special because she can bring her whole self to their relationship. He is her complement and her companion, but she doesn't rely on him for her sense of value. So, after he dies from rabies, she can mourn the loss of him and appreciate the great love that she had with him without feeling that she's lost any part of herself. in fact, for Janie, Tea Cake could never really be dead, as Joe is, for example, because she lives with the wonderful memories they shared together. This is made clear at the end of the novel when she goes back into her house after narrating her story to Phoeby:
Of course he wasn't dead. He could never be dead until she herself had finished feeling and thinking. The kiss of his memory made pictures of love and light against the wall. Here was peace. She pulled in her horizon like a great fish-net. Pulled it from around the waist of the world and draped it over her shoulder. So much of life in its meshes! She called in her soul to come and see.
This moment is what Janie wanted all along, which is emphasized in the short, declarative sentence "Here was peace." Though Tea Cake is gone, there is no sadness but a sense that her experience with him has made her life broader and given her more to look forward to. Tea Cake has helped Janie to find what she wasn't given time to discover at the beginning of the novel—the feeling of always being in bloom.
This is a very profound question and speaks to the heart of the novel. A lot of the answer can be found in the first few chapters of the book. Janie contemplates her womanhood while sitting under the pear tree. She is waiting for the other half of herself, the missing piece, the bee to her flower. She is, in essence, looking for love throughout the novel.
Her first husband offers her none of that. He is old, and though in his own way he loves her, he is more interested in using her as a farmhand than in the "romantic love" that she is seeking.
Her second husband, Joe, seems to offer her what she is looking for (at first.) But, as we see during the progression of the story, Joe sees Janie as a trophy wife. As soon as he has "conquered" her and gotten involved in the building of the town he basically sets her to the side. He does not give her the romance she wants.
She finds it in tea-cake, the only one who seems to love Janie without conditions. He is not perfect, but he is fun, he is romantic, and until he becomes rabid he is dedicated to her.
So that's what Janie is looking for...romantic love.