Deus Ex was ahead of its time, it was ambitious, thought provoking, fun, innovative and unapologetic. It aged well and still holds up, it aged better than MGS (I like MGS btw)
I can't get into this game, tried like 4 times but it's just too dated gameplay-wise. The furthest I got was the 3rd level. It doesn't help that this game is really ugly, which obviously is understandable considering that it's a 20+ year old game, but somehow System Shock 2 for example looks much better so I'd blame it mostly on art direction and colour palette.
It aged well and still holds up, it aged better than MGS (I like MGS btw)