Depends if you want to learn a 'real' language as opposed to a web scripting language. For a 'real' language I would start with something like Java, as it will force you to learn proper programming skills which will stand you in good stead to learn other languages.
For a scripting language, PHP is pretty much the best out there, certainly for the ptrice.
I would not recommend C as a first language, C is like a home surgery kit, incredibly powerful in skilled hands, but will kill you if you don't know what you're doing. C++ is the same only more so; Bjarne Strousop, the creator of C++ had this to say about the two languages - "In C it's pretty easy to shoot yourself in the foot, C++ makes it harder but when you do you tend to take your whole leg off".
Personally, I've been coding professionally for years, and throw me a language and I'll write in it (apart from Lisp and Prolog, bleugh). Most of my stuff is written in Java nowadays, though perl is my non-web scripting language of choice, and PHP for websites.
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