Deus Ex on the PS2 was a weird one. I did finish it, but I felt it should have been made for the XBox instead. It may have received the same changes as the PS2 port but at least it would have been nicer looking and might have helped getting more people to play it.
Invisible War is a good game, not a good Deus Ex game, but still a game worth checking out. The Cairo section is one of the better parts of the game, worth it for that tbh.
Then Human Revolution. For these developers first try at this kind of game it was okay, although honestly we were devoid of a game like Deus Ex for such a long time that we all lapped it up anyway. The additional DLC, the Missing Link, is where we see the developers learning from the main game and delivering something pretty good. Sadly it's delisted now and integrated into the main game, kinda weird when it's quality is far beyond the rest of the game. I'll link h.bomberguy's review here because I like the main video thumbnail.
Then Mankind Divided! With it's great gameplay, this team has oodles of experience now and they can deliver a great world with many complex systems at play that you can gawk at.
The story and themes? Uhhh...i'll let Super Bunnyhop talk on this one.
Mankind Divided's DLC is worth checking out. AGAIN the devs knew where they went wrong and delivered some great densely packed addons that moves the presentation of the game in a positive direction. It's like that saying, third times the charm, right? Their next Deus Ex game would be THE ONE.
Then Square Enix shut the studio down and canceled the sequel. Sold the IP rights to them pricks at Embracer.
Shit man, these games are complicated to make, you need to nurture and care for this kind of talent and skill. The higher ups just don't care for that sadly.