Scooby-Doo Series
Since the creation of the original series during the late 1960s, many other series of Scooby-Doo cartoons have been created, each with their own art styles and interpretations of the characters. Fans of Scooby-Doo typically have their own favorites among the series, often using the original Scooby-Doo Where Are You as the basis for judging the others. Sometimes, fans have strong opinions about series which don't measure up to the original, but whatever you like or don't like, there's something to be said for each of the Scooby-Doo series.
Four teens and their talking dog travel around in their van, which they call The Mystery Machine, finding and solve mysteries everywhere they go, mostly involving monsters and ghosts that turn out to be criminals in disguise. Who knew they'd find so many, and where did they get their talking dog? Who knows, but it's a fun show!
This format of the show ran for a couple season, then was brought back later for another season in 1978. This third season of the show is often sold in separate collections from the first two, partly because only part of the season was aired as part of "Scooby-Doo, Where Are You!" The rest of the season was aired with Scooby's All-Stars and considered part of The Scooby-Doo Show. To keep things a little less confusing, though I've decided to list them all together with the first two seasons here.
The episodes are an hour long instead of the usual half hour, and the kids are accompanied on their adventures by various celebrities, including The Harlem Globetrotters, Don Knotts, Sandy Duncan, Dick Van Dyke, and Sonny and Cher. They also had cross-over adventures with other well-known fictional characters like the Addams Family and Batman and Robin.
The show returned to its shorter format and introduced some new characters, like Scooby-Doo's cousins, Scooby-Dum (a dog that loves mysteries but isn't very bright) and Scooby-Dee (a dog actress). Some of the episodes appeared on The Scooby-Doo/Dynomutt Hour and Scooby's All-Star Laff-a-Lympics.
See Scooby Doo, Where Are You for episodes from 1978 that overlap with that series. The third season of both series was kind of split between the two of them.
This series introduced Scooby's nephew, Scrappy-Doo, who accompanied them on their travels and solving mysteries. Unlike Scooby, Scrappy wasn't scared by much and liked to put on a tough persona, always ready for a fight and talking about "splatting" the bad guys. Many people consider Scrappy to be an annoying character, but he continued as a character even beyond the series where he was introduced. Later seasons of the show (which I list together with some of the earlier ones on the series page) appeared as segments on The Richie Rich/Scooby-Doo Show.
The shows were half hour episodes, but they were made up of two shorter segments.
Unlike most Scooby-Doo shows, the ghosts in this series were real. In the first episode, a couple of ghosts trick Shaggy and Scooby into opening a magical chest and unleash 13 ghosts. Vincent Van Ghoul (a powerful warlock voiced by Vincent Price and looking like him) assists them in hunting down and recapturing the ghosts. Scooby and Shaggy travel around the work with Daphne, Scrappy, and a new character named Flim-Flam, a young boy who is also a kind of street-wise con artist (a little like Short Round in Indiana Jones and the Temple of Doom). Fred and Velma weren't part of this series.
The series takes place when the gang is much younger. In the original series, the four kids were in their late teens, late high school or early college age (they never really specify). In this series, they are about junior high age, and Scooby-Doo was a puppy. They call their gang the "Scooby-Doo Detective Agency" and solve mysteries in their hometown, Coolsville. The show was more light-hearted and humorous than the earliest Scooby-Doo series, even poking fun at itself and some of the more typical traits of the characters. There were some recurring characters, like Red Herring (a school bully that Fred usually suspected of being the bad guy, even though he usually wasn't the monster in disguise) and Jenkins (Daphne's butler, who she would call to do things for her).
The show returned to a format closer to the original series, with the the gang traveling around in the Mystery Machine and solving mysteries in different locations. However, the appearance of the characters was somewhat updated so the styles of the clothes were more modern. The series kept a light-hearted, comedic tone and some aspects of the characters' personalities were expanded or altered slightly: Daphne was still a little accident prone and into fashion and celebrity gossip, but she seemed smarter and less helpless, and she acquired some technical skills with the ability to pick locks or throw together some clever devices based on random things found in her purse; Fred became a little less sharp in some ways, still the leader who comes up with plans and traps but with more comedic elements such as his inability to learn to speak any foreign language; and Velma acquired some interests in sports which she didn't have in previous series (she turns out to be a big hockey fan), demonstrates a severe fear of clowns, and fawns over a French movie actor (being a fan of romantic foreign films). Sometimes, the series pokes fun at some of the characters' usual traits, having them change abruptly because of the circumstances of the current case. Some episodes poke fun at or change up the usual format of the episode, like having them decide to trap the bad guy before figuring out his identity (which tends not to work because there's something about the villain that they haven't figured out yet). Like in the The New Scooby-Doo Movies, some episodes also have celebrity guest stars, and there are some recurring characters, like Elliot Blender (who competes against Velma in science competitions), Melbourne O'Reilly (an Australian explorer/adventurer Fred idolizes), Gibby Norton (a creepy young scientist with a crush on Velma), Professor Ostwald (an eccentric inventor), and J.J. Hakimoto (an overly-enthusiastic director).
Although all of the gang is present in this series, most of it focuses on Shaggy and Scooby. Fred, Daphne, and Velma don't appear much. The premise is that Shaggy's Uncle Albert disappears, and Shaggy gets control of his considerable fortune. It turns out that Uncle Albert was an inventor who left Shaggy the projects he was working on along with a ton of money, and Shaggy also has to deal with his uncle's enemies, especially the evil Dr. Phibes.
This series is much darker than other Scooby-Doo series, with Cthulian aspects and alternate realities. Once again, the characters were redesigned, and their personalities and backstories gained much darker aspects. There was an over-arching storyline to the episodes that had to do with another group of young mystery-solvers in their town (called Crystal Cove) who disappeared many years ago and the evil force they were fighting.
The tone of this series is closer to the light-hearted, comedic attitude of What's New, Scooby-Doo, and the format returned to the more traditional format of the gang traveling around together in the Mystery Machine to find and solve mysteries during the summer between graduating from high school and starting college. Like What's New, Scooby-Doo, the series pokes fun at many tropes of Scooby-Doo, including aspects of the characters' personalities and their mystery-solving habits. The animation style changed (and many fans say that it wasn't for the better, which is probably the strongest criticism of the series), and some of the characters' personality traits were altered slightly. In this case, Daphne was the one whose character was most adjusted. In this series, she is still accident-prone (a permanent part of her personality since the original series) and she comes from a wealthy family (as established in previous series), but she is no longer as interested in fashion as much as she was before. In fact, her new personality trait is that she changes hobbies with every episode. She is very enthusiastic and wants to try absolutely everything that occurs to her to try (puppets, falconry, music, trying to develop psychic abilities, stand-up comedy, etc.), and sometimes, her latest hobby craze helps out the gang. In a way, she seems to be going through a kind of trying-to-find-herself-phase with trying out new interests or taking up old ones that she couldn't when she was younger (like working through various scouting patches on her own because her mother wouldn't let her join a scout troop when she was a kid). She also has great insight into her friends' personalities and uses that insight to inspire the group when they seem faced with defeat and to resolve conflicts and arguments between group members.