For me it was the Atari 800XL. Games for it came on cartridges, cassette tapes and 5.25" floppy disks. The cartridges were my favourite feature of consoles in the early days. They may have been expensive, but they loaded up instantly upon turning on the console and were very robust unlike tapes that wore out and floppy disks use to get bad sectors. I do remember waiting 10 to 20 minutes for tape based games to load, which sometimes failed midway depending on how worn the tapes were. On the other hand, they were easy to backup since they could be easily copied using a double-cassette recorder.
I was heavily interested in platform games from the start all the way up until games went 3D. My Atari favourites were Miner 2049ER, Bounty Bob and Boulder Dash. I also liked other early platform games such as Mario (Gameboy and SNES), Wario (Gameboy), Jetpack (PC) and Keen (PC). Unfortunately I have no interest in modern 3D games, so as a result it has been years since I last regularly played any games.
For my parents, it was a Ping Pong console in the 70’s.