openings
The July 2017 issue of Chess lists the top twenty openings compiled from a list of 2094 May games where both players were rated over 2400 Elo. One can not take position on this list too seriously because it is greatly influenced by how the openings are grouped. For example, all the Retis are grouped together, while English is separated into 1...c5, 1...e5, etc. Nevertheless, for what it is worth, some of the list entries are: 116 Retis, 95 King's Indians, 92 Caro-Kanns, 76 Slavs, 70 Nimzo-Indians, 63 Najdorf Sicilians, 61 1...c5 Englishes, 61 declined Queen's Gambits, 52 1...e5 Englishes, 47 Catalans, 41 Classical Gruenfelds, 41 Queen's Indians, 37 Berlin Ruy Lopezes, and 36 Kan Sicilians.
For someone seeking help with choosing openings, I usually bring up Openings for Amateurs by Pete Tamburro (2014).
http://kenilworthian.blogspot.com/2014/05/review-of-pete-tamburros-openings-for.html
https://chessbookreviews.wordpress.com/tag/openings-for-amateurs/
I believe that it is possible to see a fair portion of the beginning of Tamburro's book by going to the Mongoose Press site.
https://www.mongoosepress.com/catalog/excerpts/openings_amateurs.pdf
Perhaps janushan would also want to look at Discovering Chess Openings by GM John Emms (2006).
https://web.archive.org/web/20140627114655/http://www.chesscafe.com/text/hansen91.pdf
"Each player should choose an opening that attracts him. Some players are looking for a gambit as White, others for Black gambits. Many players that are starting out (or have bad memories) want to avoid mainstream systems, others want dynamic openings, and others want calm positional pathways. It’s all about personal taste and personal need.
For example, if you feel you’re poor at tactics you can choose a quiet positional opening (trying to hide from your weakness and just play chess), or seek more dynamic openings that engender lots of tactics and sacrifices (this might lead to more losses but, over time, will improve your tactical skills and make you stronger)." - IM Jeremy Silman (January 28, 2016)
https://www.chess.com/article/view/opening-questions-and-a-dream-mate
https://www.chess.com/article/view/picking-the-correct-opening-repertoire
http://chess-teacher.com/best-chess-openings/
https://www.chess.com/blog/TigerLilov/build-your-opening-repertoire
https://www.chess.com/blog/CraiggoryC/how-to-build-an-opening-repertoire
https://www.chess.com/article/view/learning-an-opening-to-memorize-or-understand
https://www.chess.com/article/view/the-perfect-opening-for-the-lazy-student
https://www.chess.com/article/view/3-ways-to-learn-new-openings
https://www.chess.com/article/view/how-to-understand-openings
https://www.newinchess.com/media/wysiwyg/product_pdf/9035.pdf
https://web.archive.org/web/20140627110453/http://www.chesscafe.com/text/hansen169.pdf
https://www.newinchess.com/media/wysiwyg/product_pdf/9029.pdf
https://www.newinchess.com/media/wysiwyg/product_pdf/7277.pdf
https://www.newinchess.com/media/wysiwyg/product_pdf/9033.pdf
https://web.archive.org/web/20140627104938/http://www.chesscafe.com/text/hansen159.pdf
https://web.archive.org/web/20140627022042/http://www.chesscafe.com/text/hansen153.pdf
https://web.archive.org/web/20140627132508/http://www.chesscafe.com/text/hansen173.pdf