Fuck man, I dunno. There is so much good stuff every year, and so many brilliant comics, and they cost so much and can be hard to find, so it can take me years to catch up with all the cool kids. The genuinely best comic of the year is probably something I'll get to in 2017. Even stuff I really want to read can be a stretch - I haven't even managed to find a copy of the new Grandville book yet, for Talbot's sake.
Besides, picking the best comic of the year is always an exercise in futility, because there are so many different comics in different styles with different goals, and you just can't compare them. Sam Zabel and The Magic Pen is absolutely fantastic, but I had just as much fun reading Groo v Conan. Gilbert Hernandez's Bumperhead was nice and meaty, but Judge Dredd: Block Judge by Wagner & Ezquerra had the best last page of anything I read. And there are dozens and dozens of other comics that were all enjoyable this year, in their own way, and I just really can't pick any favourite.
But, all that said, I did think BPRD #124 was pretty rad.