The original Dead Island was janky as hell but I thought it was a lot of fun to melee zombies in an island resort location. The team that made that went on to do the Dying Light series, which is a much more self-serious take on zombies but also adds a fun parkour system. There's no parkour in this, but the story is light and breezy, and the survivors all have their own personality and strengths.

I played this after Dying Light 2, which I thought had a terrible storyline, irrelevant "played choices" that made no real difference, and was just a downer in almost all respects - their world is doomed and everyone's going to die and everything you do is just applying a temporary band-aid to the situation.

Dead Island 2, on the other hand, deals with the zombie apocalypse in a much more upbeat and entertaining fashion. I happen to choose "Jacob" as my playable character, and I loved him. He was well written, well acted, and UNRELENTINGLY optimistic, and that made the destruction of Hell-A more fun. Sure the city of Los Angeles is doomed and it will probably spread to the rest of the world, but I'm having such a blast setting zombies on fire just by drop-kicking them that I didn't care.

I don't mean to say you should play one or the other - both franchises have the positives and negatives, but honestly I'd recommend Dead Island 2 over Dying Light 2, especially if you just want to have a fun time smashing zombies with modified hammers, knives, pool cues, and other weird weapons. There's good value here too - the two DLCs are very different and interesting, and as of writing they've just released a "neighborhood watch" mode that sounds like an interesting take on a roguelike. (I haven't played it yet but am downloading it now.)

So, to sum up the two games -

Dying Light 2
+Parkour, paraglide, and grapping-hook your way around a detailed, large, and often vertical city.
+Fun to kill zombies, solo or in Co-op
-Humans are the real monsters! (Sigh.) And you fight a TON of them.
-"Realistic", depressing, and negative storylines with false choices, but any choice you make has a bad outcome

Dead Island 2
+Fun and detailed real-life LA locations, with a light-hearted and satirical take on LA culture and the zombie apocalypse
+Interesting and original story that isn't just "we're all going to die."
+Fun to kill zombies, solo or in Co-op
+The Monsters are the real monsters. You do not fight a single human in this game.
-No parkour, just drop-kicks and sprint-sliding.

They're both good games, but here's my final thought: something about Dead Island 2 keeps me coming back to play another survivor or harder difficulty or the dlcs - I'm about to start a New Game+ with my ol' pal Jacob. I will never play Dying Light 2 again.

They upgraded all gold owners to Ultimate for free. That deserves me to stop being lazy and give the game a positive review

New neighborhood watch | Horde mode is awesome, People like wrong games. Dead Island 2 deserves more players. Too bad it's not cross platform.