TWD is pure filler, with the same story over and over again, they never talked about a "cure" or at least give some more information about the virus, what happened with institutions such as the us army, fbi, etc, which wouldn't have been as vulnerable as the common people. Characters cheating death only to be killed a couple episodes later, big actors wanting to leave the show when they realised it was garbage, etc.
Stranger things is a series made for teenagers, that "cheats" with all the 80's nostalgia. I could understand people within 12-16 really loving this series, maybe women for an older demographic (because of the strong, independent, female lead bs), but that's it.
Spartacus is just not top 10 material. It's top 30 perhaps, maybe top 20 if you're a really big fan of the Gladiator theme.
And Lost didn't have proper storytelling throught its latest seasons, leading to a finale that doesn't make sense and is unsatisfying for most of its fans and critics. Much of this happened because of the writers strike, which lead to many problems with schedule, a rushed and shortened season, etc. But all in all, they never had a plan for their story, so they kept improvising and just writing whatever seemed fit for the season, with a shortsighted vision. Nevertheless, it's still a top 5 series, because it showed the world the potential that tv series had (at that moment, movies where vastly superior in terms of budget, production, stars, etc), which helped in the creation of many great series.