Interesting that it's a Master System and not a SEGA Mark III!
Anyway, I remember hearing that SEGA had a fair bit of involvement in Zillion. Opa Opa is supposedly in it too. There were also two Master System games based on the series. I've only got Zillion II for my Master System, which people seem to consider the far worse game, but I had some fun with it.
I think Soul Eater is the newest anime that I really enjoyed. It's kind of in the same group as something like Gurren Lagann where I'll openly admit that it's very silly, it's at least having a fun time being silly, and that's what makes it enjoyable. Ending was rubbish, though.
As far as what was the best era for anime is, I'd probably say late 90s to early 00s.
I have never seen a master system in real life ever. Not at game shops, fleamarkets, or friend's houses. Same with the various turbografx consoles. I think I've at least seen most of everything else that was reasonably available since the mid 1980s though - even other off beat systems such as atari lynx, neogeo pocket, etc.