I'll kick off with one of mine, this one makes the 'Label' datatype full width, so you can put lots of text into the Name and Description, and it won't confine it to the left column width.

config:

<add path="~/scripts/terabyte.big-label.js" targets="editContent.aspx" />

~/scripts/terabyte.big-label.js

       
    $("div.propertyItemheader").filter(function () {
            return ($(this).next().children().length == 1 && $(this).next().find('span:empty').length == 1); 
        })
            .width("100%")
            .next().remove();

Here's a good one... Sisyphus.js - saves form data to LocalStorage to restore them after browser crashes, tabs closings and other disasters.

<add path="~/scripts/sisyphus-loader.js" targets="editContent.aspx" />

The loader script pulls in the Sisyphus.js library from GitHub directly, (you could/should probably keep this local too) ...

$(function () {
    $('#body_TabView1_tab01layer_menu_slh').append('<div class="sisyphusLoader" style="display:none;float:right;"><img title="loading" class="editorIcon" src="../umbraco_client/images/progressbar.gif" alt="loading"></div>');
    var $loader = $('.sisyphusLoader');
    $.getScript('https://raw.github.com/simsalabim/sisyphus/master/sisyphus.js', function (data, textStatus) {
        $('#form1').sisyphus({
            timeout: 0,
            onSave: function () {
                if ($loader.is(':hidden')) {
                    $loader.fadeIn('fast');
                    setTimeout(function () {
                        $loader.fadeOut('fast');
                    }, 250);
                }
            },
            excludeFields: $('#__EVENTTARGET,#__EVENTARGUMENT,#__VIEWSTATE')
        });
    });
});

... whenever you edit a form field (in "editContent.aspx"), the data/value is stored in your LocalStorage.  Think of it as a pre-save! ;-)

Cheers, Lee.

Another quick one is to set a custom favicon.ico for the back-office.

<add path="~/scripts/custom-favicon.js" targets="umbraco.aspx" />

(function (d, id, src) {
    if (d.getElementById(id)) { return; }
    var l, h = d.getElementsByTagName('head')[0];
    l = d.createElement('link'); l.id = id; l.type = 'image/x-icon'; l.rel = 'shortcut icon'; l.href = src;
    h.appendChild(l);
} (document, 'favicon', '/umbraco/images/aboutNew.png'));

Cheers, Lee.

Icon next to the General properties tab to open the current page in frontend:

 $(document).ready(function () {
    /// <summary>show icon to open page</summary>
    
    // find links property
    var linksTitle = $("div.propertyItemheader:contains('" + UmbClientMgr.uiKeys()["content_urls"] + "')");
    var links = linksTitle.next().children("a");

    // find the right link
    var url = "";
    var isDev = false;
    for (var i = 0; i < links.length; i++) {
        if (i == 0)
            url = links[i].href;

        // some conditions which URL to use
    }

    // find tabs UL
    var settingsTab = $("nobr:contains('" + UmbClientMgr.uiKeys()["general_properties"] + "')");
    var headerTabsUl = settingsTab.parents("ul");
    headerTabsUl.append("<li style=\"cursor:pointer; margin-left:15px\" onclick=\"window.open('" + url + "')\">" +
                "<img src=\"/umbraco/plugins/BackOfficePowerScripts/scripts/nw.png\" width=\"16\" height=\"16\" " +
                "alt=\"Open page\" title=\"Open page\"/></li>");
});

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