What game and why?   If it is other reasons then post below.  Features, games, developers, brand, price, hardware, etc.

If you won't own it yet, what are you waiting for?

None yet. Infamous looks interesting but I need at least 3 exclusive games and lower price.

What game DIDN'T sell me? lol

Really though, it was probably Killzone: SF. When I saw the gameplay back during the reveal in February. It just blew me away to see how the series improved from Killzone 3. Games like InFamous: SS, Knack, The Order, and knowing that all of Sony Worldwide Studios is on board just let's me know my investment will be worth it.

As much as I can't wait to play the next KillZone (for some reason, although I don't generally play FPS games, this series really resonates with me) and Drive Club looks like it has a lot of potential.

The reason I'm getting a PS4 is their attitude towards indies and the whole "we're going to go back to lots of smaller more diverse games" from the PS1 era and the fact that their First Party output is so diverse and pretty boundary pushing.

360 was my console of choice at the start of this previous generation, however, Sony won me over (for the first time) with their mid life exclusives like Heavy Rain and Uncharted 2 and Infamous, so of the 3 consoles, I also expect the PS4 to have a similar lineup throughout it's lifecycle, rather than blowing it's load in the first couple of years.

Sony... mostly Naughty Dog

But at launch, Watch_Dogs was the most exciting game, but now I guess that falls to Killzone Shadow Fall

In terms of the actual games, the trio of Watch_Dogs, Destiny and inFamous Second Son really excite for the start of next year more than the actual launch titles

For me nothing has sold me yet but Killzone is a big part of why ill buy one. Most likely ill be buying one because of Naughty Dog :)

The hardware alone sold me the most to be honest. 7 years playing on the same system, it's about freaking time to upgrade.

Games: Killzone, Rime, and inFAMOUS: Second Son

Although I'm very hyped for Killzone, honestly the third party games and loyalty to Sony is why I'm getting a Ps4 as soon as it's available after launch (didn't pre order).
Plan on getting Bf4, maybe Ac4, Killzone, 2k14, Resogun, and all the playstation plus games for launch.

So far only Killzone SF and Infamous.

Infamous Second Son because i loved the first two and they are by far my favorite exclusive first-party offerings from Sony