If someone hasn't played the Deus Ex games yet, the whole series is available with a massive discount at GOG now! Compared to the first one (I'm playing it right now), how are the others?
Invisible War is the black sheep of the series for a reason, but it's still a good game with, in my opinion, a pretty good story. It's too streamlined for its own good (though the plot/setting actually explains a lot of that), and the terrible engine results in way to much loading between small sections. Still, worth playing. I'm one of its defenders.
Human Revolution is the only time I've seen a series change hands completely and for the new guys to 100% pull it off. It's fucking great. I still need to finish it though. (I got it ages ago, then rebought and restarted it for the Director's Cut stuff.)
Never played Mankind Divided, but I'm looking forward to it.
You can safely ignore The Fall unless you're a mega-fan who has a morbid curiosity with janky, obscure, technically canon side stories. It was made as a somewhat impressive mobile game ported to Steam. It's not very good.
Deus Ex Go is a fun, well-made entry in the Go series, for what that's worth.