If popularity is not measured in the sheer amount of code written or programmers, then I would have to say Java. It has to be the most publicly shamed language. It's not really the language itself I enjoy. It's IntelliJ. Seriously, IntelliJ makes writing Java code insanely fast.
The latest version of Eclipse IDE (Luna) is actually quite good and possibly better than IntelliJ for Java development.
Have you used Intellij? It's quite possibly the best software development tool ever made. Sometimes I just gawk at how polished it is. Intellij IDEA is simply amazing.