Definitely start with the video of the OBC. It's available on Watch Instantly on Netflix and the DVD is readily available at many stores. The cast has never been beaten (though a few members have been equaled in following productions) and the video is presented without any cuts. After that, any cast recording you get is up to your personal preferences.
The OBCR has problems. The sound can feel very off and tinny on certain numbers, but as CATSNY mentioned, all 3 cast recordings are very similar in terms of content included. True, it doesn't have "Our Little World," but I've personally never found the appeal of that song. It's pretty, but it's really not needed.
The OLC is...odd. A lot of the performances are just strange but the orchestrations are similar to the OBC with a ton of little touches that make you appreciate new aspects of the music. This is also probably the least appetizing of all three cast recordings in terms of singing. Imelda Staunton and Julia McKenzie are both fantastic, though. I would recommend you listen to it last, so that you can judge the material separately first and then decide how you feel about this... interesting interpretation of the show.
And finally the much debated revival. There are some things to recommend. Laura Benanti, Greg Edelman, Christopher Sieber and Vanessa Williams (Prologue aside) are all wonderful. Beautiful vocals and a great sense of the tone for the show. However, I really hate all of the changes to certain songs ("On the Steps of the Palace," "Hello Little Girl," "Las Midnight" among others). They all just take most of the subtlety out of the show. Still, Benanti's "No One is Alone" is haunting, both of Edelman and Sieber's "Agony"'s are fantastic and Williams' "Stay with Me" and "Last Midnight" are very well done (altered lyrics notwithstanding).
So after all of that: DVD, OBC, Revival, OLC. Then decide for yourself which recording you prefer.
"Sing the words, Patti!!!!" Stephen Sondheim to Patti LuPone.