My first Atari was the 400. As a kid, living in a town where the only stores for electronics was Sears (Atari VCS) and Radio Shack, I had planned to get a VCS like my friends for games, and a TRS-80 Model 1 for computing (My best friend got me on programming by dropping a Sinclair ZX-80 (updated to 81) in my lap). Then our family visited JAFCO in a nearby larger city where I found the Atari 400. My mom suggested it for both games and programming.
I had the opportunity to purchase an 800 which were on sale to make room for the XL line. But by the time I got to the store, they all sold out and I bought the 800XL instead. This system served me very well for a long time, adding a 1050 disk drive, a 1030 modem for our local BBS and a SIO to Centronics adapter to attach a Panasonic KX-P1080i printer. Eventually, I sold that system to get an Atari 1040ST. I didn't really do as much with that system as I did with the 800XL (mostly due to the lack of available game and development software for the ST in my town). Traded the 1040ST to a clone XT retailer (looking for an ST to do some graphic art for his business) for a newly built XT clone, which I used through my university years and my first tech job.
Throughout my childhood and university years, I still had my 400 as a gaming console. I briefly had a 1200XL I found in a pawn shop. Eventually, both found new homes after I finished college.
As an accidental vintage computer collector (started about 6 years ago or so), I now have in my collection the 800 I wanted in my teen years; it was gifted to me just before the 2020 VCFPN (which got cancelled due to COVID) by Joe Decuir (we are both fellow members of the Seattle Retro Computer Society). I've spruced it up, picked up some tools and the Macro Assembler to get into writing some tools and try recreating some of my BASIC games in 6502 ML - just for fun. Got some games so my son and kids that attend our SRCS meetings with their parents can play them. Its amazing on how much I still remember about this system through the decades. And I'm pleased to discover that I have not lost my edge at Star Raiders... :-D