It is really a matter of taste. The original '82 US theatrical version, which had the tacked on 'happy ending' of Deckard riding off in his spinner with Rachael (imposed by the studio/completion guarantors to lighten up the 'mood'), plus Ford's narration, doesn't fit with Scott's intended vision. It also doesn't make sense when the world presented throughout the film is one that's been environmentally destroyed beyond redemption (thus, there wouldn't be vast expanses of green forests as the one shown in that ending!).
The International version released in 1982 features more violence and gore and, despite still having the 'happy ending' and Ford's voice-over narration, manages to be darker in tone and mood.
The 1993 'Director's Cut' deleted the narration and the happy ending, but was a rush job as Ridley Scott couldn't be personally involved in it due to his Christopher Columbus film's duties at the time.
I still haven't seen the workprint version, so can't tell you anything about it. That leaves the new 'Final Cut', closely supervised by Scott himself, who worked on its restoration since 2000 together with his DVD producer Charles DeLauzirika.
I'd say go for the 'Final Cut' first, and then see the others for comparison of the variations in the different versions.