* Usagi Tsukino (Sailor Moon) and Mamoru Chiba (Tuxedo Mask): They are the main couple and share numerous romantic kisses throughout the series. The first kiss happens in the very first episode, and their relationship deepens with each kiss.
* Rei Hino (Sailor Mars) and Yuuichi Kageyama (Zoisite): Their relationship is complex and tragic. While they share a few passionate kisses, Yuuichi's ultimate betrayal leaves Rei heartbroken.
* Minako Aino (Sailor Venus) and Artemis : Minako and Artemis share a deep connection, and their relationship is often portrayed as playful and teasing. They share a few romantic kisses as well.
While other characters may share kisses in the series (like the inner senshi with their respective guardians), Usagi and Mamoru's romance is the central love story and is most prominent in terms of kissing scenes.
Keep in mind that the anime and manga differ slightly in terms of the number and context of kisses, so your perception might be influenced by which version you watched/read.