Okay i am about to buy this baby

It's not new out i don't think,it just caught my eye
Anyway i noticed that it has all 3 versions(Original Theatrical Version-1977,Special Edition-1980 and Directors Cut-1998)
Question/s 1:Which version should I watch?,is there a version that stands out more than the other two? or basically-which version do you usually watch?
I have had the Close Encounters of the Third Kind Collectors Edition on DVD for ages(2001 release)

But I am not even sure which version that is,it just says this on the back of the DVD case that i have
The film was re-edited by Steven Spielberg in 1980 and re-released as The Special Edition including the now-famous final scenes inside the Mothership. Now for the first time on DVD the best existing film elements have been remastered and digitally enhanced in High Definition format to present the film's sound and visual effects at their very best.
Question 2:so,is the DVD i already have the 1980 Special Edition? or another version?
(doesn't really matter if i am getting the BR set with 3 versions,I'm just wondering)