Thief™ 2: The Metal Age

Found this on a best all time video games list. THe graphics are pretty dated but it's all about sneaking around and it's reasonably fun. I'm not blown away but I like it.

Great atmosphere, sound and world design. Maps are well build and objectives and story are great. You can do missions largely your way, be it via conventional way, which often may require procurement of keys, or maybe you search around a little to find a secret entrance.

Like most of the other Looking Glass Studios games this one is also a masterpiece. If you are looking for a stealty thief game, this is the one. No one has ever done it better than the Thief series.

Oldies but goodies! I will always love playing these games

I've been playing this game (and Thief Gold) since it was first released and I love it still. The first two games in the series are true gems and were for me a radical departure from what I thought an action game was. Sneak, steal, blackjack anyone who gets in your larcenous way. Make your way across the rooftops or crawl through the sewers. Steal the purse right off a guard's belt. Find all the loot. Hide from creepy mechanical security faces, or find a way to turn them off. Or throw caution to the wind and blow them up! Tiptoe across marble floors to pick a bank clean. Aim a water arrow into a steampunk robot's boiler and listen to its dying musings. The graphics are basic at best, but still the missions were gripping and complex and without a doubt I'll be at it again soon.