Print the ASCII printable character set

Brainfuck, 30 27 bytes

+[[>++<<+>-]>]<<<++[<.+>++]

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How it works

+ changes the initial cell to 1. After this step, we enter the following, nested loop.

[        While the current cell is non-zero:
  [        While the current cell (C) is non-zero:
    >++      Increment the cell to C's right twice.
    <<+      Increment the cell to C's left.
    >-       Decrement C.
  ]
  >        Advance to the cell to C's right.
]

This computes consecutive powers of 2 until the the value 256 = 0 (mod 256) is reached. When the outer loop finishes, the tape is in the following state.

                                     v
001 002 004 008 016 032 064 128 000 000 000

<<<++ retrocedes three cells and increments twice, leaving the tape as follows.

                         v
001 002 004 008 016 032 066 128 000 000 000

Now we're ready to print the actual output. As a stop condition, we increment the cell above twice each time we print and increment the cell to its left. Since 66 + 95 × 2 = 256 = 0 (mod 256), we stop after printing all 95 printable ASCII characters. We achieve this as follows.

[      While the current cell (C) is non-zero:
  <      Retrocede to the cell to C's left.
  .+     Print its content and increment.
  >++    Increment C twice.
]

Brainfuck, 40 39 bytes

++++[->++++[->++>++++++<<]<]>>>-[-<.+>]

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Explanation

++++[->++++[->++>++++++<<]<]

The nested loops basically mean you multiply the number of plusses together, so 4 × 4 × 2 = 32 in one cell and 4 × 4 × 6 = 96. Here is the tape after running this:

00 00 32 96
 ^

---

>>>- moves the pointer to the fourth cell and decrements it. Now we're done with the setup. 32 is the code for space, the first printable ASCII character. 95 is the number of characters we have to print. Here is the tape now:

00 00 32 95
          ^

---

[-<.+>] runs until the current cell (the fourth one) is zero. It decrements the counter and prints the character and increments it for the next time.

Cheddar, 29 bytes

->(32:126).map((i)->@"i).fuse

Range from 32-126, loop over it and get the string at the given char code @" and the fuse together (join)

Cheddar, 7 bytes

32@"126

Unfortunately this is broken as of the current release but I'm sure you can go back some versions where this works