HW's are all too confusing on the different characteristics that people hunt after. I could see that collecting first editions of castings might be a worthwhile pursuit. My HW collecting is the same as Tex's though in that I only buy what I like. There are just some HW's that are too strange for my taste.
These days, pretty much only regular issues/first editions that look interesting along with some of the Classics and Ultra Hots.. I've been into Hot Wheels since I was a kid in the early '70s, so I have a ton of them...
I have or had every car they made from 97 to 2000. Then Hot wheels went crazy! So now I only collect the cars I like. I am trying to get all the T-Hunts. and scooters. I am still selling some of my stuff on the bay and working on customs.
I collect the First Editions, with a few others that strike my interest. I'll get variations if I see them, but I won't go out of my way to hunt them down...after all, I still want to have fun and not get stressed about it.
I used to try and get all the f/e for each year since I started collecting. But since so many hot wheels are rediculous stupid looking made up cars, I have all but quit hot wheels. I only buy the ones I REALLY like now, and have begun selling off all the rest of them. I now concentrate on JLs, and recently picked up my first greenlights.
I haven't had my Hot Wheels collection out in awhile. It's sitting in tubs in my basement. Someday I will have the full collection on display. I am looking for those first editions as well. Have fun pulling your first's together, it's an addiction, man...but some of them are just to cool to pass up!