Select2 - Select2 offers customizable select box with support for searching, tagging, infinite scrolling, and many other used options.
Bulma - Bulma is an open source CSS framework based on Flexbox and built with Sass. It's 100% responsive, fully modular, and available for free.
Bootstrap - Simple and flexible HTML, CSS, and JS for popular UI components and interactions
Material UI - A CSS Framework and a Set of React Components that Implement Google's Material Design
Materialize CSS - A modern responsive front-end framework based on Material Design
Selectize.js - Selectize is a custom <select> UI control with autocomplete and native-feeling keyboard...