Thief series is great, for the most part.
If you like stealth, original two are awesome. Missions are great, but you must play stealthy or forget it.
Deadly Shadows is also great, but a bit different. It's more of an open-world game with good-to-great missions, story & lore.
Thief 2014 tries to do the Deadly Shadows formula, but w/ more moderizations - i.e. Highlight items, Arkham X-ray detective mode stuff, one hit knockout key, etc etc...which you can shut off/turn off each and every one, in custom difficulty mode to suit your play-style.
Thief 2014 is good, but isn't as great as the other 3 games. Namely, the missions were often good, but not great. Also, I think they should've fleshed more out on the "Erin will kill vs. Garrett normally doesn't kill" story & philosophies; and fleshed their characters out more.