mark greene: thank u katie, for being my last patient
or maybe when the chopper landed on romano
then again there's marl goodbye to rachel, and his letter
or when greene told carter he sets the tone
or when doug totally messed up his medical career

The episode where Mark Greene finally realises that he loves Susan and runs after her to the train station, only for her to go....
And when Mark died....
In fact...all of it!!!!

when abby and luka had their wedding, has got to be one of my faves. i cried at that episode!!!!

couldn't agree more. i don't think i could pick out my fave episode. it has to be all the ones i have seen from about series 5

One of mine is "Take the Long Way Around". Where Carol is stuck in the little store and tries to take of all the people inside. After that episode she made my list for Top 5 Favorites of ER cast member.