Without a doubt, this was Ross's Best Performance in FRIENDS. Ross Geller is crazy as a drunkard who's trying to adjust to the fact that Joey & Rachel are together. Notable scenes are the one where he makes the toast to 'Love' & when he brings the hot plate of Fajitas.
Chandler is spot on with his inappropriate jokes and accidentally revealing wrong things. (he revealed to a boy that he was adopted and that Santa wasn't real & also to Frank's triplets that Phoebe gave birth to them)
Monica is at her usual - being the clean, perfectionist she is.
There's not much scope for Joey & Rachel to act for this episode. They just put up with it.
Phoebe is also good for this episode wherein her deep inner desire of trying to adopt one of Frank's triplets almost comes true.
So overall, this episode was one of the bests. Just when you thought that FRIENDS is ending and there may not be much left to see now, this episode proves you wrong, and it does that so well. This episode was almost reminiscent of the times when FRIENDS was juts new & young, & at its best. Do watch over & over, guaranteed to make you laugh out loud every single time :)