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It depends on the position. Overall it's the two Rooks. Larry Kaufman did a highly praised study published in the 1990's in Chess Life of 80,000,000 positions where he determined that a Queen is worth 9 3/4 Pawns, a Rook 5, a Bishop 3 1/4, a Knight 3 1/4, a Pawn 1.
Of course Rooks are worth more when connected to each other than not, so, again, it's the position.