I agree with those who have said it's too early. Not only are there still games to come out later this year, but who's had time to play large numbers of 2014 games? The games I've played the most this year came out in 2009 and 2013, and I'm not sure I've played any games that came out this year (it depends somewhat the definition of a launch across platforms). So I can't nominate any games that came out this year.
scheva007 is also definitely right about quality varying over time. Civ4 wasn't that good in 2005, but by 2008 it had become a really good game. So, by 2008, you could argue it was the best game that came out in 2005, but it wasn't the best game that came out in 2005, in 2005. It also doesn't really work well with games that are continuously improved over time, like Minecraft or Prison Architect.
5 Nights at Freddy's was this year, I think, unless it had a low-fanfare release in 2013. Haven't played it myself, though.