(I generally loathe the PMS trope so I'll just bypass all things related to that)
+) Winston: "I'm a single man now. So basically I have to be able to trick women into thinking that I can buy them stuff." GIVE US WINSTON ON THE PROWL PLZ.
+) Nick being super excited about not being the poorest now.
+) Nick being irrationally angry 365 days a year montage. Child Nick calling someone a shyster was like sweet nectar to my soul.
+) NICK AND HIS MAGICAL NEW BEST FRIEND. Everything about this killed me. The staring contest with a strange man on a bench evolving to forming a strange bond with a dude that does not speak a word as Nick babbles his nonsense non-stop and experiences epiphanies. OMG THE WATER THERAPY. And how quickly his discomfort segued into glee and his insistence that he apply it to everyone in his life for their troubles. UNSUCCESSFULLY, OF COURSE.
+) Happy!Nick is like when that really cute boy in your class gets a horrible haircut and suddenly loses all of his allure. THAT WAS ME WITH HAPPY!NICK.
+) Nick and Jess having another "I believe in you" moment.
+) "Jump Around" Schmidt chant bathroom party!!!!!