Battlefield will have the same multiplayer as the third entry, if you liked it than you won't be dissapointed. Also the single player campaign seems to be very similar, so a lot of eye candy and scripted events, to cater to the Call of Duty crowd, for me personally it is like non-existent.
Killzone SF will definitely exceed in single player campaign, but we pretty much don't know anything about the multiplayer component now, and given how much the single player changed since Killzone 3, we really don't know what to expect. There is also the thing of what you prefer technical-wise, cause Battlefield will be 60fps with sub-par visuals, Killzone SF 30fps with better visuals, from the gameplays it looks like a rock solid 30fps stable framerate, so I would go for the latter, but that's just me.
Damn,my standards must be pretty low. I thought cod ghost looked good xD
Maybe it's just not my cup of tea you know. I mean, I really liked the scripted events in CoD WaW they were like a fun one timer, but further, they were just pushing it for me. Although I only say that from my brief gameplays of the Modern Warfare series at friends, as I never felt they are worth buying. They keep the same style for the Ghosts. Honestly Ghosts is like by far on the bottom of my list, I don't see a single thing that makes the game look better than BF4 or KZ SF, I thought of buying it wouldn't even remotely cross my mind, when I can choose from all of these titles at launch.
But as I said that's just me. Even though I'm not sure if the direction GG are taking KZ SF is the right path, as it is very different than both entries in the series before it. I am a big fan of Killzone and am willing to give it a chance. Since BF4 won't be as gimped as BF3 was on consoles compared to PC on the multiplayer front, I consider getting it as well later down the road, cause the MP is rightfully praised. Although I honestly hope that we'll get more info on Star Wars Battlefront on PS4 soon, with like a 2014 holiday release so I don't have to buy BF4 and have this game instead :D