My introduction to lisp happened in 1985, 3 weeks before my wedding, when, as a co-op student, I was sent to Cambrige, Mass. for 2 weeks of training at Symbolics. (My way of helping with the wedding was to stay out of the way until it was time to show up for the ceremony.) Ever since then, I have done most of my professional programming on Symbolics Lisp Machines. The last couple of years I have used Xanalys' LispWorks on a Linux PC.
At one time I (as a civilian) managed a lab of 12 Lisp Machines: 6 Symbolics 3650's, 5 TI Explorer II's, and one LMI (a TI Explorer by any other name) for the U.S. Army. I also taught an 8 week course in how to program LispM's.
I have since changed from civil service to the private sector (as a government contractor). I now work on various (Lisp based) projects related to printed circuit assembly manufacturing and product data standards (ISO 10303). My current project involves maintaining an open source application (Express Engine) for working with ISO 10303 based schemata and data populations.
I just recently discovered CMUCL and SBCL. I think that either of them combined with McCLIM and a set of CLIM based tools (Editor, Lisp Listener, Windowed Debugger, etc.) would make an excellent development environment.