Selecting a whole line of text, including the newline
What if you want to select 78 here (after having pressed ⇧↑)?



Or if you want to select both 12 and 78, on Windows you couldn't press shift+home and shift+end.

Methods like moveToEndOfLineAndModifySelection: are unanchored in most applications, which means that they always extend selections. They are actually anchored in Xcode, TextMate, Sublime Text, and BBEdit, but I don't know any way to change the default behavior.

If you just want to make selecting and deleting lines easier, you can create ~/Library/KeyBindings/ and save a property list like this as DefaultKeyBinding.dict:

{
    "~l" = selectParagraph:;
    "~z" = (selectParagraph:, deleteBackward:);
    "~x" = (selectParagraph:, cut:);
    "~c" = (selectParagraph:, copy:);
}


After reopening applications, ⌥L should select a line. See http://www.hcs.harvard.edu/~jrus/site/cocoa-text.html and http://lri.me/keybindings.html for more information.