That depends on what kind of game you are in the mood for. Things are a bit different than they were a year ago. Now there are enough games for the new consoles that you can be a bit more picky about what you want to play. There aren't a ton of PS4 exclusives yet but you can probably get a pretty decent price on inFamous Second Son or Killzone at this point. I really liked inFamous but yourbeliefs and meStevo weren't as high on it as I was. Luckily the third party studios have started to step it up recently.
The very first thing I suggest you do is get a PS Plus subscription and start adding all the free games to your library every month. You can do that from the Sony web store before you actually have your PS4
here. That way you will have a decent selection of games from day one.
The PS4 game I have been going back to for the longest is still Diablo 3. It's one of the better bang for your buck games if you are into loot driven RPGs. It's not really the game to show off the power of your new PS4 though. It looks fine but it doesn't have that wow factor that some of the other games have.
If you are into RPGs with a little more visual flare Dragon Age: Inquisition came out today and got very positive reviews. This is another bang for your buck game. IGN's reviewer mentioned that he put 90 hours into his first playthrough.
If you are into shooters there are a lot more choices. Far Cry 4 came out today and I highly recommend at least checking out a video review. There is so much to do in the Far Cry games and I'm really looking forward to this one. Simple things like taking out an enemy outpost are fun because there are so many options for getting it done. You can lure a wild bear, tiger, etc into the camp to take the guards attention off you, you can take them out one by one with stealth and sabotage the alarms, you can set up outside the camp and pick them off 1 by 1 with a sniper rifle, you can cause a fire to trap them, you get the point.
In Far Cry 3 just about everything was fun to me. I never even finished the game because I spent so much time doing side missions and hunting animals to get the specific skins I needed to craft items. Exploring the world was fun enough that I didn't always feel the need to go to the next mission. Some of the animals are tough to take down and it can get pretty dangerous. The sharks in particular are pretty scary. I think Far Cry 4 would be a good place to start. The only reason I rented Dragon Age first is because I want to buy Far Cry 4 when it goes on sale and not have to worry about how long I keep it. Although, Dragon Age is huge enough that I might end up buying that before I finish it too.
Call of Duty: Advanced Warfare is a good choice if you want a mix of campaign and solid multiplayer. Wolfenstein has a good campaign but no multiplayer. Then there is Destiny which could easily be the only game you play for months. It's got the solid shooting mechanics of a Halo game with the loot drive of Borderlands. Temporary events are always being added to give people a reason to stick with it.
The good part about waiting a year after a console is out is that you have lots of good choices now. There were months where I basically played everything that came out because there wasn't much available but we are past that now. I would watch the video reviews on IGN for some of the games I mentioned so you can see some gameplay in action and just pick what looks most appealing to you.
Edit: There is also GTA V if you didn't play it on PS3. That was a great game and the upgrades they did for PS4 look pretty awesome.
