Actor Jonathan Harris, left, who portrayed Dr. Zachary Smith and co-star Billy Mumy, who portrayed Will Robinson, are shown in a scene from the 1960s sci-fi show, Lost in Space.

AP

Imagine a network that lets you watch Michael Bluth torch his family’s banana shack, Malcolm Reynolds outsmart the Alliance, Peter Petrelli and Hiro Nakamura save the cheerleader and the world and Ted Baxter’s bumbling infuriate Mary Richards on The Mary Tyler Moore Show.

Now envision picking and choosing which episode you want of each show and when you want to watch it. Add features such as being able to start and stop, fast-forward and rewind at will. And a network where commercial breaks eat up no more than 30 seconds instead of 5 minutes.

And best of all, it’s free.

Television doesn’t love us that much yet, but the Internet is getting closer with the launch of Hulu.com, a streaming video site that brings legal, studio-quality (read: not YouTube graininess) video to the Web.

How it works:

Start at www.Hulu.com. You won’t have to download any software. You can search for shows or movies directly, just like you would with Google, or browse titles by popularity or alphabetical order.

The window you use to watch the clips, shows or movies comes with a handful of nifty features, like a lower-lights button that darkens the browser.

The site has also made sharing video insanely easy. With a simple click, you can e-mail it to a friend. Or you can clip the video by moving your cursor or even embed it in your social-networking site on MySpace or YouTube. And the picture knocks the socks off most of the video you’ll find on the Web; it’s beautifully clear and doesn’t freeze or drag.

Hulu is a godsend for catching up on old favorites — welcome back, Buffy! — or series you missed the first time around.

For a startup that just launched in March, the number of titles is impressive — more than 250 series, 100 feature-length films, plus clips from 150 more TV shows and 50 movies, such as Saturday Night Live and Napoleon Dynamite, as of press time — and growing.

What doesn’t work so well:

Critics have pointed out that CBS and ABC aren’t on board with Hulu, so you can’t watch Lost or Jericho. But you can find them. Go to Hulu.com and search for Jericho and you’ll get links to online episodes at CBS.com.

A Lost search gets you links to ABC.com.

Sometimes the omissions are just plain heartbreaking. A search for Freaks and Geeks, Judd Apatow’s spot-on look at high school in the early ’80s, yields no results.

And finding the episode that you want can be frustrating because some series have only a handful of episodes on the site. Want to laugh at Homer Simpson? You can. Want to watch the deliciously titled “The Crepes of Wrath,” where Bart heads off to Paris as an exchange student? You might be out of luck.

Some series have as few as five episodes available for viewing, though the site is adding new videos often.

That’s frustrating if you’re trying to do more than catch up on a week you missed. Hulu says it plans to put up new episodes the day after they air, but that only works if the site has rights to the series.

Plus, some major shows, such as American Idol, are missing. (The company did strike a deal with the National Basketball Association for sports content, though.)

Why Hulu matters:

Americans watch lots of video on their computers. More than 12 million people paid for this kind of content last year, according to a study by Parks Associates, a research and analyst firm that studies how people use the Internet.

Broadband users watching full shows online weekly doubled from 8 percent to 16 percent in 2007, according to market-research firm Horowitz Associates.

Greg Mansur, an instructor in the Department of Radio-TV-Film at Texas Christian University, says he expects that number to grow.

“I want content that I can watch when I want to watch it,” he says. “And if it’s free, I’ll put up with a few commercials.”

Even though lots of sites, including the networks’ own, already do that, Hulu is still important because it’s one-stop shopping.

For example, you don’t have to go to a Warner Brothers store to buy I Am Legend and then to a Disney store to buy Enchanted. You just go to a store like Best Buy.

With Hulu, you don’t have to move from site to site to watch shows from different networks like Chuck and Prison Break.

While some sites already compile content from various sources, experts say that Hulu offers easier access and better quality.

Plus, Hulu has shows, like Married … with Children and Lost in Space, that you can’t get at network sites.

The result, says Kurt Scherf, a principal analyst with Parks Associates, is that Hulu has the kind of setup that allows users to stumble upon shows that they might not have discovered otherwise.

What this might mean in the future:

Part of the reason TV junkies are so excited about Hulu is that it signals a change in network thinking, says Fred Singer, chief executive of Anystream, a company that readies video content for Web streaming. Instead of holding onto content, networks are now making it available to different sites on the Web.

The idea, Singer says, is that eventually networks like NBC can make enough money from their programming being watched on the Internet that the Nielsen ratings on TV will be less important.