When did you first try Lisp seriously, and which Lisp family member was it?
Common Lisp in Mid 2002-ish

What led you to try Lisp?
I think it was emacs. IIRC it went something like this:
I had a really boring job at my university so I was spending my time "Trying new things" such as Dvorak and languages I'd been wanting to learn. I was also a bit of a vi fan. I didn't know much about emacs and I wanted to know what was so good about it. I'd tried it a few times but didn't see the big deal so I went and did some proper research. During my investigation I found out it had a built-in lisp language. I'd heard a little bit about lisp so I did some more research on that and came accross lisp evangelists everywhere such as Paul Graham and the ALU. What struck me was that though there was plenty of people who seemed to love lisp, unlike every other language I'd looked at hardly anyone had much to say against lisp other than "yuck, parentheses". So I decided to learn it.

What other languages have you been using most?
Prior to lisp I didn't enjoy programming much at all. I loved computers but decided I'd rather do systems administration kind of work on unix platforms. Consequently, other than learning Haskell and Java during my university course I was more inclined toward languages such as C and perl since that's what I encountered most in sysadmin work. Needless to say, I hated it when I was forced into a situation when I actually did have to do some programming. Oh, and I guess I did a fair bit of webby stuff like HTML and javascript.

How far have you gotten in your study of Lisp?
I'm trying my hand at the nitty-gritty now. I've gone and bought Lisp in Small Pieces and am planning to try to write a lisp machine code compiler to kickstart an operating system. I've done research on Genera and would like to see something like that resurrected so I hope to eventually make a start on such a project. I've also done a little playing around in SBCL's source code. I haven't memorised the whole ANSI spec or anything but I certainly feel comfortable coding in common lisp.

What do you think of Lisp so far? Well, like I said before; I used to hate programming. After I picked up lisp I couldn't get enough of it. Now I code purely for the fun of it, going out of my way to find new projects to work on. It just fits with my way of thinking. I love prefix notation and the functional programming paradigm. Infix and syntactic punctuation has always annoyed me and now I have an alternative. And of course macros are great! I can't think of any way a language can become as powerful as lisp without becoming lisp simply because of macros; where the programming structure is in the same form as one of the language's main data types such as lists in lisp, the idea of getting your language to rewrite your code for you comes naturally. Meanwhile I can't think of any way lisp (as opposed to lisp dialects) can be improved as a language.