In America Master System was such a massive flop that a whole lot of us did not even know it existed until we became adults and got home internet. Least of all stuff like Sega SG-100. So I guess for the United States market especially, it was their Genesis. An awful lot of Xennials like me grew up convinced Sega Genesis was their very first home console. I;m used to the name Genesis, but obviously I know what a Mega Drive is these days, so I'm really fine with either or.
I sometimes just say "I loved Boogerman, I played it a lot on the Genesis MD back in the day". Pretty interesting to find out in my 20's they had older consoles at all, least of all that Master System was actually fairly successful and had a long life in other regions (and that Saturn was a huge success story in Japan with software support as late as 1999!!!) with good software support. Even moreso when I learned how close my Sega GameGear was to just being a portable Master System.
Their was a number of things wrong with that model though, it's very much not recommended. My understanding is that it wasn't even actually made by Sega at all. It was farmed out to the infamous cheapo company Majesco. Not exactly known for high quality, that company. It's also the worst compatibility with the library of games and terrible sound quality.
Majesco did cartridge reprints of SNES games, you can sniff them out because they say "Assembled in Mexico" and are cheap low quality carts that tend to have issues. (MADE in Mexico SNES carts are just fine though!)
Their was a "glitch" or flaw in the OG hardware that could actually be utilized to make games do things not really thought possible before visually. They "fixed" it, and in doing so broke quite a few games on it.