Which "programming language" I have been dealing with for these days ? (Winter of 2008)

If you're interested in learning new technologies on programming languages and the global development environment you have to be fresh and robust.

Nowadays, i have fully concentrated my leisure time on learning new programming languages that run the web. I was always asked "Which programming language is the best to learn?" by my friends and co-workers, i generally answer this kind of question like that: " If you only know one, then your in serious trouble" :)

This got me thinking on what programming languages should a programmer know to maximize his talent and marketability. Below is the top five languages that every programmer should know:

Ruby on Rails

Why you should learn it: Cause it is the future. If you want to build a website writing only 8 lines of code Ruby on Rails(RoR) is the language for you. There has always been talk of Object Oriented Programming(OOP) and Ruby on Rails is OOP in its purest form.
Why it is not my first choice: Cause it is still in infancy and it does not have a debugger or a true IDE. Also its has a STEEP learning curve and its hard to understand how each component is put together, but all in all, it is the newest, most innovative one and very interesting with pure futures.
Resources: Top 12 Ruby on Rails Tutorials