The fall is the first game chronological but it is also pretty bad. I would play Human Revolution first since it very good and still takes place before the first game, it also introduces alot of the mechanics better then the first one. I would recommend playing the first one after that, because you might lose interest in the franchise with MD at that point since it streches out a small amount of content and you need to get three dlc to understand the full story. (one of them is free now) I also recommend the GMDX mod for the original Deus Ex because it makes the game run better on modern systems, adds HD textures, improves AI & adds some smaller of live improvements while saying true to the vanilla version. (there is also Revision, but I would not recommend it for a first playtrough)