What was the most significant moment in the history of Ted and Lily's friendship on How I Met Your Mother?

On the hit TV show How I Met Your Mother, Ted and Lily's friendship had many memorable moments throughout the nine seasons. One of the most significant moments in their friendship was when Ted asked Lily to break up with his ex-girlfriend Karen on his behalf. Lily, being the caring friend she was, agreed to help Ted and convinced Karen to move out of their apartment. This act of kindness solidified Ted's trust in Lily and showed that she was a true friend who always had his back.

Another significant moment in their friendship was when Lily revealed to Ted that she had been sabotaging all of his relationships in an attempt to keep him single and available for her best friend Robin. This confession caused a major rift in their friendship, but they were able to work through it and come out stronger on the other side.