There is no episode where Stabler almost kisses Benson in the original Law & Order: Special Victims Unit series. While their relationship is complex and filled with tension, they never cross the line into a romantic relationship.
However, in the spin-off series, Law & Order: Organized Crime, the characters do share a kiss in Season 2, Episode 13, titled "The Last Man Standing". This episode explores their complicated history and feelings for one another, culminating in a passionate moment.
While their relationship remains a major point of discussion among fans, their interactions are primarily focused on their professional partnership and their shared history.