Mass Effect imo. It didn't even get proper outrage, it just released with as much excitement as a wet fart, and now ME is probably dead. Really friggin sad, because the game was not terrible just mediocre, and ME was probably my favorite new IP last gen :(.
Anthem better not suck, or else I'll lose all hope for Bioware who used to be one of my favorite studios in their heyday.
NMS has been getting consistently better overtime to the point I think that they've redeemed themselves from total disaster to be a divisive niche space game (which is where they should have been from the start if they didn't go way too wild with marketing). Also I personally liked the game from the start, but I'm a sucker for the aesthetic and that's all I really bought it for.
Battlefront 2 was mediocre, but seems like it has been very financially successful. I have no interest in it, but I never perceived its mixed reception as a huge failure, and tbh it didn't seem like the controversy hurt sales alll that much.
FO76 looked like hot trash from the outset and might be the game that looks like the worst quality of all the four to me, but it seems like a pretty obvious quick cash grab to hold Bethesda over until next gen. We'll see if there's any real damage whenever Starfield and TES are revealed.