Tyler and Nova
Since Catelynn has her issues (ie. being glued to the couch) it seems that Tyler is the main caregiver for Nova. The scene at Butch's party where he was rocking her to sleep was very sweet. I actually can see Tyler being a good dad (he has his problems but I don't think they'll prevent him from being a positive parent). I'll bet he's learned a lot of what not to do from Butch and what to do from his mom. If only Cate could just wake up and realize that Nova's babyhood is passing her by while she sleeps and smokes weed and puts all of the responsibility on Tyler.
The only thing constant in life is change