Oh, I think the only platinum this year I got from Call of Duty: Advanced Warfare. It was really really hard to get, especially reaching Level 50 in Co-Op. I tried it countless times online, but the people there just always weren't good enough. So in the end I just did it all alone. I think that itself took me about a month.
I am most proud actually not about a platinum, but a gold trophy. All the way back in 2009 I believe I managed to beat Zico in Wipeout HD! It's the hardest trophy I ever got, seriously. When it comes to platinum, I think Killzone 2 was the hardest, as you had to be among the top 1% players in the world in one week to get it.
Next up is definitely Fallout 4, but I just don't have enough time to play it. =(