All good things must end, and certainly, our favorite television series are no exceptions to this long-standing rule.

This time of year is filled with all kinds of good-byes on television. Some shows leave us with season-ending cliffhangers, while others say farewell forever in series finales.

Of course, I have my favorites. For instance, the Grey’s Anatomy season finale was simply breathtaking. Another medical drama, ER, said goodbye forever after 15 years on the air. I admit I’m a little short on time these days, so I had strayed from my faithful viewership of ER as of late. But even if it has been a while since you’ve watched a television series you used to view religiously, there’s a twinge of nostalgia when you hear it is going off the air. That’s part of the magic of a well-hyped series finale – the proverbial one night stand that provides a chance to say goodbye to an old friend, even if it is one you haven’t seen for a while.

Clearly, we are a nation addicted to television, and some series sendoffs are among the highest-rated programs of all time with a staggering number of viewers tuning in.

Many people know that the M*A*S*H series finale, which aired on Feb. 28, 1983, was the most-watched show of all time with 105.9 million viewers. I don’t remember watching it at that time, but I imagine most people do. I’ve seen it several times since in reruns.

In case you were wondering, here’s a list of the other nine top series finales of all time. They are: 2. Roots, Jan. 30. 1977 (36.38 million households); 3. Cheers, May 20, 1993 (80.4 million viewers); 4. Seinfeld, May 14, 1998 (76.3 million viewers); 5. Friends, May 6, 2004 (52.5 million viewers); 6. Survivor, 1st Season, Aug. 23, 2000 (51.7 million viewers); 7. Magnum P.I., May 1, 1988 (50.7 million households); 8. The Tonight Show Starring Johnny Carson, May 22, 1992 (50 million households); 9. The Cosby Show, April 30, 1992 (44.4 million households); and 10: All in the Family, April 8, 1979 (40.2 million households).

I must say that I was a bit surprised at seeing Magnum P.I. on the list, but I guess you never know what’s going to draw viewers.

As a loyal viewer of any television series, it’s always hard to say goodbye after so many years.

Just recently Jay Leno bid farewell to the Tonight Show. He had been host since Johnny Carson left in 1992. The show has had only five hosts since it began in 1954, including the most recent, Conan O’Brien, who began his stint just last week.

For many people, television shows become like old friends that you welcome into your home every night, in the case of The Tonight Show, or every week, M*A*S*H, for example.

Some might even argue that television is no longer worth watching when certain shows end. Honestly, if you can even manage to sift through all the reality shows and news-based broadcasts, it’s difficult to find some old-fashioned entertainment that was offered by shows such as M*A*S*H, Cheers, The Cosby Show or All in the Family. These are on the top 10 most watched list for a reason. I grew up watching most of these shows. Seeing the reruns now and then always brings back fond memories of when watching television meant a sweet escape from reality into the world of entertainment.

But as television shows come and go we are reminded that change is constant in the entertainment world just as it is in life. Things grow, evolve and inevitably have to end at some point.

There’s a very touching moment when the series, The Wonder Years, aired its finale in May of 1993. Anyone who watched the show remembers it was set in 1968-1973 (each season took place exactly 20 years before the then-current year). The series tackled the social issues and historic events of that time, such as civil rights, the ’60s revolution and the Vietnam War, through the eyes of the main character, young Kevin Arnold. It was narrated by Daniel Stern.

These are a few lines from the very end of that last episode: “Growing up happens in a heartbeat,” Stern says. “One day you’re in diapers, the next day you’re gone. But the memories of childhood stay with you for the long haul.”

Sometimes I miss the popular shows of days gone by the ones that made that top 10 list when they finally said goodbye. Television, like so many things these days, just isn’t what it used to be, and that’s unfortunate for all of us.

Mullally is a Tribune writer.