Chosen

Chosen is a JavaScript plugin that makes long, unwieldy select boxes much more user-friendly. It is currently available in both jQuery and Prototype flavors.

Select2

Select2 is a jQuery based replacement for select boxes. It supports searching, remote data sets, and infinite scrolling of results.

MagicSuggest

MagicSuggest is a multiple selection auto suggest combo box for Bootstrap 3.

multiselect

This is a user-friendlier drop-in replacement for the standard with multiple attribute activated.

Simple Combobox

A combobox plugin

Listbox.js

Listbox.js is a simple jQuery plugin that provides a more powerful alternative to the standard `select` tag

jQuery easySelect

A plugin to present multiple select elements in easier way.

Shuttle

A jQuery plugin that is a shuttle box ui.

jQuery Touch Multiselect

jQuery plugin to have a touch-fitted multi select input field..

dproCombobox

A combobox plugin