LUKE SKYWALKER
Whether or not one appreciates how Disney has handled the character of Luke Skywalker, one of the most iconic heroes in cinema history, all fans can agree that there's much to be explored during the time period between the Original Trilogy (OT) and the Sequel Trilogy (ST).

LEGACY CHARACTERS
Many of us have been saddened by the fact that we never saw the Legacy characters all together on screen (Luke, Leia, Han, Chewie, Lando). This series could do that. 

THE NEW REPUBLIC & THE NEW JEDI ORDER
Additionally, it hurts to see them work so hard to establish the basis for a New Republic and a New Jedi Order in the original trilogy, but we never get to see the fruits of their labor on screen. The Sequel Trilogy wipes both out before we really get the chance to explore them. For many of us, the prospect of seeing these elements was what most excited us about the Sequel Trilogy. 

LIVE-ACTION VS. ANIMATION
At this point, an animated series would probably be the best way to go, particularly with the absence of our beloved Carrie Fisher. Either way (live-action or animated), we'd love to see Mark Hamill come back for this series. 

If the series is live-action, we'd like to see minimal de-aging and minimal uncanny valley moments (the latter being the low points of the otherwise excellent Rogue One). Unfortunately, this would require having the series mostly avoid the Legacy characters, when they are who we want to see the most!

If the series is animated, let's push to make it HAND-DRAWN. Maybe environments and backgrounds and other inanimate elements could be CGI, but we want to see fluid characters, with a great and emotional style. Technology is key for Star Wars, but so is nostalgia. Those of us who grew up with the OT also grew up with hand-drawn animation. Something in the vein of the style of Hayao Miyazaki would be most welcome, given the ability of that style to convey the magic of this galaxy. But Titmouse's Galaxy of Adventures has been looking great, too!

THE FORCE
While we loved Solo and are excited for The Mandalorian and the Cassion Andor series, the Force is the mythological backbone of the Star Wars galaxy. It would be wonderful to see Luke and his students (including Ben Solo) gathering information and artifacts related to the Jedi, but also beyond the Jedi - the Bendu, the Whills, the Nightsisters, etc. We want to see an expansion of the mythos and believe that this can be done while still preserving the mystery and magic of the Force (which Rogue One did with Jedha and The Guardians of the Whills). Many of us who enjoyed The Clone Wars loved the seeing the main characters in action. There's plenty of room for other characters (like Ahsoka) to even become the focus of the series, but we had an in-road to the series through the regular appearances of Anakin, Padme, Obi-Wan, Yoda, etc. We would love to see the Legacy characters appear frequently in the series (if not be the main characters of the series). 

TIMELINE
While there could be flashbacks to the foundational moments of The New Republic and The New Jedi Order, we would like to see this series start in medias res - with new adventures set in this timeline. In other words, the work of establishing the New Republic and the New Jedi Order is done, and we get so see them both in action (though with all of the disfunction of the New Republic, and all of the eventual darkness in the New Jedi Order surrounding Ben - a narrative show needs conflict, after all!). Ideally, the series would begin just before Ben enters the Jedi Order (establishing the character's hopes and dreams early on, making his fall that much more powerful - though this could be done with flashbacks, too). Ideally, the show would end on the low note of Ben's "betrayal" (if that's what it really is, after seeing Episode IX), the start of The Knights of Ren, and then Luke heading into hiding, leading immediately up to the main plot points of Episode VII. 

CONNECTIONS
This series would likely be the one that resolves the ending of Rebels, with Thrawn and Ezra eventually coming back (making Ezra the "Bridger" between the OT and ST) - maybe a season or two into the show - and perhaps bringing with them all of the mystery/darkness of the Unknown Regions that sparks Ben's descent into the dark side.

CONCLUSION
We want to see time, energy, talent, and money/resources given to this mostly unexplored era, in the form of a truly excellent series. While we think a hand-drawn animated format would be best, a must would be want more of the Legacy characters during the era that shows the fruition of what they fought so hard for in the OT.