Alphapolyglot, 8 languages, 37 bytes, score 0.072265625

8 "6";;7iiiio hkaeeeaeaeawxzz ax zaCM 

Features AlphaBeta, Beatnik, Commentator, Deadfish~, evil, Foo, Golfscript, and Husk. Thanks to Leo for helping with Husk.

Explanation

AlphaBeta

8"6";;7iiiio hkaeeeaeaeawxzz a # Garbage x z # Clear register 1 and 3 a # Add 1 to register 1 C # Set register 3 to register 1 M # Output register 3 as a number 

Beatnik

iiiio hkaeeeaeaeawxzz ax zaCM is 5 50 9 17.

5 50 pushes 50 (2 in ASCII) 9 outputs the top of the stack as a character. 17 exits the program.

Commentator

There are 3 spaces in the program, each one increments the active accumulator.

Deadfish~

8"6";;7iiii # Increment 4 times o # Output as a number h # End program kaeeeaeaeawxzz ax zaCM # Garbage 

evil

8"6";;7iiiio hk # Garbage aeeeaeaea # Increment and weave the accumulator to 53 (5 in ASCII) w # Output accumulator as a character xzz ax zaCM # More garbage 

Foo

8 # Garbage "6" # Output 6 ;;7iiiio hkaeeeaeaeawxzz ax zaCM # Garbage 

Golfscript

8 # Push 8 "6" # Push the string 6 ;; # Pop and discard twice 7 # Push 7 iiiio hkaeeeaeaeawxzz ax zaCM # Garbage 

Husk

The first line is executed first.

8 # Return 8 

The second line isn't executed.