is the one where mike wants phoebe to get rid of gladys and she gives it to monica but then mon doesn't want it and tries to give it to rachel and so on and so forth...

but the thing i remember the most about the whole episode is the scene while the credits are running, where rachel takes the painting and stands at joey's door while he's sleeping to get him back for doing the same to her earlier in the ep. that made me :lol: and i woke up my roommate (i was watching a tape of it at 2 AM)