Dead Island Definitive Edition worth buying?
I own riptide on ps3 and never played it yet.
Depends on if you own DI (original w/ all DLC content) already + how you actually feel about that game.
Same goes for Riptide, also.
I've felt for a long-time, Dead Island is the definitive open-world first-person ARPG zombie-smashing experience. Riptide's good + has the cool new defense-mission addition (which this series really needed) - but it ain't on Dead Island's level b/c DI felt so fresh at the time. Riptide feels more like an expansion than a sequel, TBH.
Basically, DI Definitive is the same (as the original) game, but this version actually comes w/ all the DLC - but of course w/
much better graphics, lighting, textures + whatnot. It's on the newer Techland engine that Dying Light's on, actually.
If you never played Ryder White DLC, it's actually pretty important to the DI story b/c there is a part of the story in the base-game that feels missing, as the end of the DI base-game has this major twist + turn - which felt rushed, under-developed & not explained. Ryder White DLC - which is story-based entirely & you cannot level-up Ryder in this DLC, BTW - fully clues you in & connects the dots here as to why a few certain things happened early-on and at the end of the DI base-game.
Same pretty much goes for Riptide on the Definitive Edition - same drill. Definitive has all the DLC's, but it's not like there's really anything exciting + necessary there for DLC's, TBH.
If you're buying the HD Remasters, it's going to be for the better graphics textures & features stuff + if you want ALL the DLC content. If you own the old versions on PC, make sure you catch the HD remasters in a major discounted sale or something - b/c that's the best way to buy it.
EDIT:
Dead Island: Definitive + DI: Riptide Definitive were once 80% off ($3 each) for game-owners on Steam for pre-order - of course, that (Pre-Order) Loyalty Deal's now dead. You might want to wait for some kind of sale like that again, especially if you do own the originals.