I love how HTML5 focuses so much on semantics rather than just syntax.
I'm currently getting a kick out of learning how to do CSS3 animations.
Why make a static website when you can use Javascript to give it life?
When it comes to making huge web applications, AngularJS takes the cake for client-side development.
For large-scale webapps, Groovy/Grails is my absolute favorite for back-end programming.
I'm not amazing at it yet, but I love Wordpress when it comes to developing websites instead of webapps.
Since most of the things I've done are secured, I've made some screencasts showing a few things I've made.