Apple - Remap Ctrl+C, Ctrl+V, and Ctrl-X only

One option would be to use DefaultKeyBinding.dict, but it wouldn't work in all applications or text views.

{
    "^x" = cut:;
    "^c" = copy:;
    "^v" = paste:;
}

KeyRemap4MacBook would work almost everywhere, and it also allows excluding specific applications.

Here's the definition of the remapping selected in the screenshot:

<item>
  <name>Use PC Style Copy/Paste</name>
  <appendix>(Control+C to Command_L+C)</appendix>
  <appendix>(Control+V to Command_L+V)</appendix>
  <appendix>(Control+X to Command_L+X)</appendix>
  <appendix>(Except in Terminal, VM, RDC, Emacs, X11, Eclipse)</appendix>
  <identifier>remap.copy_paste_winstyle_no_term</identifier>
  <not>EMACS, TERMINAL, VIRTUALMACHINE, REMOTEDESKTOPCONNECTION, X11, ECLIPSE</not>
  <autogen>--KeyToKey-- KeyCode::C, VK_CONTROL, KeyCode::C, ModifierFlag::COMMAND_L</autogen>
  <autogen>--KeyToKey-- KeyCode::V, VK_CONTROL, KeyCode::V, ModifierFlag::COMMAND_L</autogen>
  <autogen>--KeyToKey-- KeyCode::X, VK_CONTROL, KeyCode::X, ModifierFlag::COMMAND_L</autogen>
</item>