I would like to know if this game is winnable for black? Black to move but unsure of the pieces that would give black a better advantage. Any help would be greatly appreciated.

r5k1/pp1qpr1p/3p2p1/2pP4/1n2P3/1P2N1Pb/2PQ1P1P/3RR1K1 b - - 0 1
Black has an overwhelming advantage and should win easily. Being up by a whole piece is a huge advantage that basically can't be overcome by purely positional considerations.

The most straightforward way for Black to win is to try to trade pieces and end up in an endgame where he has one piece to White's zero; a win at that point would be trivial.

He could also try for a kingside attack, since White's light squares are very weak.