I've worked on quite a few front-end projects over the years, and most of my work and experiments are available at CodePen, but I've embedded some of my favorites below
Fair warning, some of these may not play well with older versions of IE
This example uses the Velocity.js framework to help out on the animation to create a cool 3D effect when the card is clicked. Probably not all that applicable to most sites, but I thought the effect looked nice. This is also, somehow, my most popular Pen on CodePen by far.
This project assigns the current time to a hex value, constantly counting up. The color changes every second, though the effect is pretty subtle initially...but if you're here when the hour changes over, get ready for a show!