Casey Kasem was a never-can-say-goodbye kind of guy. And that's part of the reason he came up with his signature catchphrase, "Keep your feet on the ground and keep reaching for the stars." It beat saying "so long."

Upon retiring from the weekly radio countdown show American Top 40 a decade ago, he explained that he didn't want to get mushy at the end of his final episode. "When I signed off, I just said, 'And don't forget, keep your feet on the ground and keep reaching for the stars,'" as usual, he told the New York Times. "I just didn't want to say goodbye. Every station I was at, I never said goodbye — when I was in Detroit, Cleveland, Buffalo, Oakland, and L.A. I don't know why."

But there was inspirational intent behind the weekly signoff, which Kasem came up with when he was a local DJ in Michigan in 1956 and subsequently used for a solid half-century.

"I’m just delighted that back in 1956, I had enough foresight to recognize that if I could deliver a message that reflected my values, I would be making a pretty good contribution to young people who might be inspired by it," Kasem told Billboard in 1997. "It’s a wonderful thing when someone tells me that they know exactly what the expression means, that they get the message. I’d like to believe that we all need some guidelines in traveling down the road of life... I don’t know that I’m that much different than I was back in those days, (although) I believe that my basic principles, my sense of ethics, my values through the years, have been honed and sharpened."

Although he was hardly known for being much of a preacher in-between the hits, Kasem certainly did maintain a sense of personal integrity off the air, especially when it came to the causes closest to his heart. Although he did thousands of commercial spots and voice-overs, he refused to put his voice or imprimatur behind anything involving animal products, being a strict vegan. That included cereals, because they're usually served with milk. “I just turned down a Cheerios commercial because I didn’t feel this is something I would want my child to eat," he once explained.

But generations of kids associated him with cereal anyway, having spent their early Saturday mornings hearing him as the voice of Shaggy on Scooby-Doo, or doing characters on Batman and Robin or Transformers.

In honor of the king of countdowns, here's a ranking of some of the moments and tropes associated with Kasem over the decades, along with some lesser-remembered rarities:

10. Shaggy, we love you (too): Here is a rare clip of Kasem doing the Scooby-Doo character's voice in the flesh, on a Jerry Lewis telethon.

9. He was Los Angeles's local equivalent of Dick Clark in the mid-'60s: At certain points it was about the visage as well as the voice. Kasem hosted an L.A. TV show called Shebang from 1965-68 on KTLA.

8. The random voice work: You never knew where you might hear those sonorous tones pop up... even on an LP extolling the virtues of astrology.

7. The parodies, like the hits, just kept on comin': Harry Shearer was renowned for his impression of Kasem, on screen and on the radio. But here's Dana Carvey's equally famous take on Kasem.

6. Pranksters couldn't resist getting in on the Kasem action, either: Here's a famous phone prank from the Howard Stern show that had a sampled version of Kasem's voice calling for takeout.

5. His none-too-probing interviews: Kasem treated all the stars who came onto his show equally and without judgment, from the pop greats of the '70s to the rappers who started popping up in the '80s...to KISS, when they were promoting the concept-album bomb Songs From The Elder.

4. Making things smooth and easy: Kasem always wanted to soothe his audience, especially when they were confronted with some pop development they might have found perplexing...like this new thing called "compact discs."

3. The long-distance dedication: Kasem introduced the concept on L.A. radio station KRLA in 1964, when he got a letter from an Oakland girl named Elaina who had met one of the Beatles and wanted to share the experience with the world as well as her boyfriend. It went over so well on the air that Kasem actually cut a single called "Letter from Elaina" for Warner Bros., reciting the dedication against a backdrop of an instrumental version of "And I Love Her" arranged by George Martin. (It only made it to No. 101 on the charts, thus well avoiding making Kasem's own countdown.) It eventually became a mainstay of his show called "Letters from the Sweetheart Tree" before he added the dedications to American Top 40 in 1978. "Of all the things I do on the show, that may be the most important one outside of playing the music," Kasem said.

2. His good-natured philosophy: He explained it in a Coast to Coast interview.

1. The sign-off: Here's his very last one, from July 5, 2009. Although he turned over the reins of American Top 40 to Ryan Seacrest in 2004, he kept other variations of the show going for another five years, with the emphasis more on adult-contemporary formats. Five years ago, he said goodbye to the airwaves for good with this barely elongated but typically unsentimental sign-off. His feet are no longer on the ground, per se, but longtime listeners are hoping he's among the stars he urged them to reach for.