Well, at least IMO.
They all have their good moments, but basically Coach is a douche, Nick is whiny and annoying and Schmidt keeps thinking he's better than anyone else.
But Winston it a great guy.
Coach was about the only normal one on the show. Winston is ok when he doesn't get all weird, which means any time the episode is about him he's going to be annoying.
I like the show when it doesn't go more than quirky. The episodes where they are bat-sh!t crazy and immature about something are mostly annoying.
What I've noticed about the Nick and Winston characters is that they're more unlikeable now that they're in their mid-30s, Nick especially. Whenever I catch the show, I find myself wondering how they are okay with living and behaving like college roommates at their age. Winston wasn't as clumsy and goofy in season 1. They dumbed him down a whole lot. Schmidt is the only character that seems to have matured more as the seasons went on. Not saying he's not immature, just that he's more mature than when the series started, imo.
I disliked Coach. He was too mean-spirited.
Yeah, that is a big issue for me. Being quirky is one thing. Being a completely spastic moron who can't even deal with every day issues or situations once you've passed age 30 is mostly pathetic.
Not that I expected them to turn 30 and now become all serious, but Winston can't say hello, Nick can't step over a pile of laundry...