Trying to convince a friend to buy a PS4, and he wondered what some of the best games are. So any help would be appreciated.

RULES: If a game already has been mentioned, do not mention it again (Unless its Bloodborne, Bloodborne deserves all the re-mentioning it gets)

Everything from Indies and 3rd parties to full exclusives are allowed :)

Knack

Is there anything else worthy of being noticed?

Why bother convincing? Let them be a grown up and decide themselves, that way if they regret their purchase you won't get shit over it.

Rocket League

That's a tough question as everybody has different taste.

I enjoyed The Order 1886 but I'm sure you'll find many that would disagree. From what I hear Infamous SS is really good and Bloodborne.

Infamous SS is a great game and if you like it you can buy first light too. If you are a fan of the souls series Bloodborne is the game for you; the best from software game imo. Killzone SF looks amazing but I haven't played it so I cant tell you how good it actually is. The Order 1886 is an interesting game but it's awefully short, you probably should wait till it drops under 20euros or they give it away on PS+. You should also check out the PS+ edition of driveclub, the best looking racing game I have seen.
Now for multiplats I have bought DA:Inquisition and the Witcher 3 both good RPGs. We also got rocket league last month for free which is incredibly fun and addictive. I'm also planing to get MGS V in the near future.
Finally if you didn't own a PS3 last gen you might want to get the remasters that are coming out. The Uncharted trilogy and the last of us are truly must play games.

Drive Club

Here is a nice list for your friend: http://www.metacritic.com/browse/games/score/metascore/all/ps4?sort=desc

Basement Crawl and Godzilla