Both of them are quite good. Titanfall 2 was... well, the first Titanfall was amazing, just hamstrung by dumb development choices like map packs and a campaign that wasn't really a campaign and wasn't singleplayer.
Titanfall 2 has an SP campaign that is... better than I'd have expected, although a bit short, and so far Respawn have promised there'll be no more paid map packs. There'll be more maps, but everyone will get them. It's a genuinely brilliant game, though perhaps slighly undermined by its release date, putting it straight between the year's two main FPS releases (the latter of which contains the remaster of the game Respawn's team was behind, Call of Duty: Modern Warfare, and seemingly very much the inspiration for Titanfall's SP). I also continue to be impressed by what they manage to make the Source engine do, though it'd be nice to see the game also make its way to Steam at some point.
Battlefield 1 is an unusual transplant of the traditional Battlefield formula into an era better known for trench warfare. It also surprises by having a decent SP campaign in the form of War Stories (a rarity for any Battlefield game). The multiplayer is pure Battlefield at it's best, but the greatest part of this game is how the battlefield changes over the course of the round with explosives carving gouges into the ground to make foxholes which serve as makeshift cover. The Behemoths are a great addition as well, allowing a suffering team a chance to get a foothold back into the game. The Operation modes are basically an extended form of the Rush mode, where one team pushes for territory over several rounds and 2 or 3 maps, with the attacker retaining ground gained over each round. The attackers also get buffed between rounds if they aren't making headway to improve their chances. It's good fun that takes maybe a little over an hour.
As for Call of Duty. I've started the Remaster, and it doesn't look like there was a massive change other than an improvement to the graphics, though the purchase may be worth it alone if it brings life back to MW's fantastic MP scene. Need to play Infinite Warfare too, but I can't say I'm expecting much.