i bought every version, but when the newer one came out, i either sold the older one at a cheap price to someone i know, or just gave it to them for free.
I only have a DS Lite. By the time I was ready to buy a DS, the Lite had been announced so I just waited for it. I don't see a need to upgrade to a DSi either, so I'll probably stick with my Lite unless something happens to it or I get a really good deal on a DSi.