What do you currently play?
Black Repertoire Suggestions

You should first learn how to move the "plastikakia", and bother about opening's theory after you have reached 1800-1900+ FIDE.

There is french and sicilian after 1. e4 beside ...e5. Any other is peculiar.
That's the most absurd thing I've ever heard! There are other mainstream openings besides the French, Sicilian, and 1...e5. The Caro-Kann isn't peculiar, and neither are the Pirc, Modern, Alekhine, Scandinavian, etc.
And as for other lines, they still aren't peculiar. They are unorthodox. These would include the Universal System (1...d6 w/o a Pirc or Modern setup - these tend to lead to either French, Caro-Kann, Pribyl, or Philidor setups), Owen's Defense (1...b6), Nimzovich's Defense (1...Nc6), etc.

@ThrillerFan Maybe i choose wrong word. I mean 'peculiar'. Sorry, if that is the case.
I saw your blitz games and you play 1. ...d6. And you have better ranking than me.
My point is, caro-kann, pirc are quite complicated and i have feeling that in some lines twisted (hope that is right word with no negative load in it). Personally i think Alechin and Scandinavian are second cathegory openings with hard play for black out of opening. I may be wrong. I'm not so good to understand chess on titled level.
I hope GreenLeaf14 will be smarter after this thread.

hypermodern systems against 1.d4, like kings indian,benoni(plus benko), neo-grunfield, queen's indian.
form's gambit against 1.f4

If you currently play the French vs e4 then the Dutch (with move order 1...e6) vs 1d4 is an obvious choice.
You don't mind if it transposes back into a French after 2.e4, and you avoid the early anti-Dutch systems that club players love like 2.Bg5 and 2. e4
i disagree with all the above said, when you learn openings you dont learn moves, if you learn good openings from good teachers you learn strategies and ideas. Sure strong masters as pfren or people who play their entire life chess can do without. But most people when they dont learn openings cant develop deep and good ideas and play the most obvious stuff.
if you learn to understand openings, the plan the ideas, it will enhance your chess. you wont be mister obvious, you will the master of the subtle moves.

I am just under Pfren's limit. I have won and lost games in the opening, lost more than won.
Its a phase of the game like any other, and unlike the ending, you know you are going to have an opening.
Masters spend 90% of their time on the opening, and 10% of their time telling everyone else don't bother with the opening.

Masters spend 90% of their time on the opening, and 10% of their time telling everyone else don't bother with the opening.
because theyve mastered opening principles, basic tactics and basic endings. The people they tell not to bother havnt.
Though openings are fun.

The French is very solid. Stick with it don't change for a few years.
Don't get too deep into opening theory right now, stay with tactics, endgames and solid positional play.. and play alot.
Endgames are really more important than openings as they will never change. Knight vs Pawn, King vs Pawn, Blockades, Queen vs Pawn, King and Pawn vs Bishop. Endgame strategy and theory is a better investment of time and will yield more progress. My .02
I am thinking of expaning my repertoire as black and i was hoping u guys can help.What do you suggest me ?If possible some lines with no so much theory,any suggestions are welcome:)