Learning Lisp

So /prog/ serious question - I'm honestly just hoping for a good answer. I'm getting more and more interested in Lisp - some people may think the Syntax and the functional concepts suck, but I don't; It's the opposite actually. I think it's really interesting.

Now there are more than one Lisp dialects:
    * ANSI Common Lisp
    * Scheme
    * Arc
Just to name a few I read about while informing myself about Lisp. (Arc seems pretty cool btw.) Would you suggest learning Lisp? I already know Python but am interested in learning more - specifically other programming languages and thought Lisp would be pretty interesting.

I'm just a bit worried about which dialect I should actually learn. I think I'm going to start with ANSI Common Lisp for now (since it's the standard) and maybe take a look at Scheme and Arc afterwards. What would you guys suggest me?

Also is Lisp, or any dialect of it suitable for general-purpose scripting? Basically the things I do with Python:
    * Webscraping
    * Text editing
    * Renaming files
Just to name a few.

I recommend Croma. Croma's partly an attempt to correct everything I see wrong with CL/Scheme (1 namespace and continuations like Scheme, but all sorts of everday useful stuff snarfed from CL like proper lambda-list keywords and so on). It also sticks in various experimental things: 1st class macros (bad idea, I've since decided). I spent a while re-thinking assignment, and Croma uses a strange new idea of “overloading” the values of data objects: you can add in an additional function value (sort of like CL) that'll be used instead of its value in the _function_ position if it exists, to make possible assignment that's generalised and extendable but also idiomatic.

All of this is geared towards an integrated continuation-based web development system. Using a fairly elaborate standard library, you can do stuff like (link "Click here" (fn (hdrs) (str 'you 'clicked "me")) in the middle of HTML pages. And, of course, it gets rid of HTTP transactional/statelessness cruft, as has been documented by Graham and Queinnec.

Croma's not quite in a world-useable state, but it's getting there. I'll GPL it as soon as I think others might find it useful, anyway.