Each subreddit thinks the other game is amazing and that the other game company cares more about it. For UT/MT I'd say that FIFA is better, but for offline gameplay modes 2k takes the cake. Both are broken as NBA 2K18 MT in online though.
I probably enjoy NHL better than either of those, eventhough BBall is my fav sport. FIFA is good, but you have to decide if it is good enough to entertain you for a year.
I've played both for quite a long time, I'd say if you play offline 2k is miles better, online depends on modes you play.
FIFA 17 been playing fifa since fifa 09 the fifa gameplay is cheesier, the game has little to no effort put into it, the devs don't care about the gameplay if theres a bug you can bet it ain't getting fixed and the new features they've added like "sbc's" are really only there to make EA more money.
Ultimate Team - Easier to build a good team in 2k but nothing will compare to FIFA Ultimate Team. The most addicting game mode. Career - Both are good but 2k is a little more in depth.
Online - ProAM allows you to team up with your buddies with your created player and play against other teams around the world/ customizing your court and jerseys.
I have both, offline 2k no question. Online it depends, I like Pro Clubs way more than ProAm/Mypark, but if youre willing to grind 2k offline as if youre working an extra job, you might be able to enjoy 2k online as much.
Also I really like the career mode in FIFA as opposed to 2K, it doesn't have the terrible cut scenes & terrible story like 2K, I also like how you can loan yourself out to other teams to play & periodically get chosen to play for your national team.