If I can only buy one which should it be?
I guess it depends, are you already a fan of CoC? if so it would be easier just to grab it and add some pulp flavor to your game. Since it is a supplement, it requires the main rules. HEX on the other hand is a nice system with beautiful production values. Ive ony gotten to play it a few times at GenCon but it was a very simple game and very enjoyable. my only beef was its one roll combat system.
Yeah, if you already own and like CoC 7e, Pulp is a great supplement for that. I'm currently running the Two-Headed Serpent Pulp Cthulhu campaign and we're having a lot of fun with it.
I haven't gotten to play HEX yet, but Seth Skorkowsky just put out a review on it the other day here (https://www.youtube.com/watch?v=4OEbfdO907o&t=0s). Looks like fun, although he points out that the hardcover is out of print right now and the softcover doesn't match the pdf, so that would put me off it until they start printing the hardcover again.
I prefer the pulp Cthulhu system but I had fun with HEE.
Quote from: Thanos;1050704If I can only buy one which should it be?
They're both good.
Therefore, I'd advise you to pick which default setting you like better, and buy the system that goes with it;).