C++ started as C with objects, today it is one of the most widely used langauges in the world
Go was meant to dethrone C++ as the lowlevel weapon of choice. It has a great standard library.
Haskell is a purely functional language. It may be a bit hard to learn, but it is powerful, and (probably) worth the effort
Java was created by Netscape for it's browser. For years it was considered a toy language (it arguable still is by some). In later years the language has evolved (with ES5 and ES2015 as well as with NodeJs) and is now widely used for both web development (client and server side) as well as in Desktop applications
Lisp is one of the languages with most dialects. Clojure, Racket and Emacs Lisp are all "lisps". Lisp is the second oldest high level programming langauge still in use. Only Fortran is older - so lisp predates e.g. C
Lua is a lightweight interpreted programming language, usually used as an embedded scripting language in larger programs
Perl was the defacto scripting language for many programmers for years. It has been nicknamed "The swiss army chainsaw of scripting languages". It directly influenced Ruby
PHP was originally invented do lightweight programming in html pages (the name was originally a recursive acronym: Php:Hypertext Preprocessor). Today PHP is one of the most used languages for Complex websites. E.g. Facebook and Wikipedia was originally written in PHP
Ruby is a scripting language, originally intended to be an improvement of Perl, today it (mostly because of Rails - perhaps the most used web framework in the world) it powers a lot of Web Applications. Ruby is easy to learn, and there exists a ton of libraries for it.