Unless you want multiplayer, just go with Prepare to Die Edition plus the dsfix mod for 60 FPS. The remaster really does look a lot worse

Tfix Lite and EAX Sound fix are mandatory to start playing, and I highly recommend first time players install Gold2Dark to convert your copy to Thief: The Dark Project. It has far better pacing and it's much more accessible. Whether or not Gold is better overall is debatable though, either way it's second only to Thief 2 as best stealth game ever made.

As of December 2023, there's no doubt it's better than 2, but I'm no longer as confident as I was with 2 that given time, it would be the ultimate comprehensive Warhammer strategy game.

Blows my mind that people aren't saying it's massively better than the last one in every way, I can't think of a single area that wasn't improved

Single most overrated game of all time. Pretty good, but not great