Like those people in aprons at the big-box store passing out little squares of cheese, a number of streaming services have responded to the Covid-19 pandemic by giving out free television samples. The series they’re putting in front of their paywalls are a loss leader, a handful of candy to get you to subscribe. And therefore their availability is temporary: HBO’s free series will require a subscription again in just over a week, and others, while technically open-ended, won’t be around forever. Here’s a look at the best series on offer and how long you have to watch them free. (And in most cases without registering for a free trial and surrendering your credit-card information.)

‘The Sopranos’

HBO

No other network’s quarantine come-on has been as generous: HBO has unlocked premium shows like “The Wire,” “Silicon Valley,” “Veep,” “Barry,” “Six Feet Under” and the endlessly entertaining “Succession.” First among equals, though, is “The Sopranos,” the series that single-handedly remapped the possibilities for TV drama when it appeared in 1999. James Gandolfini and Edie Falco gave two of the most powerful performances in the medium’s history as a New Jersey mobster and his wife. (HBO Now, through April 30.)

‘Baseball’

PBS

With the baseball season going and possibly gone, PBS offers Geoffrey C. Ward and Ken Burns’s 18-plus-hour documentary history (the length of about six major-league games) as an armchair alternative. Released at a time when the sport’s future didn’t seem entirely secure — the 1994 World Series was canceled, because of a player strike, four days before the show’s premiere — it’s an exercise in both artisanal nostalgia and poetic boosterism. Donald Hall, the author of “Fathers Playing Catch With Sons,” says, “I think we have some hope that baseball might look like baseball a hundred years from now,” a prediction that’s looking a little premature. (PBS.org, open-ended.)