Build my own list
If you liked

Space: 1999

1975–1977 · 2 seasons · ITV1

New and upcoming (2026 and later)

Out this year, or not out yet.

Star Trek: Starfleet Academy

2026 · 1 season · Paramount+
space
Paramount Plus PremiumParamount Plus EssentialParamount Plus Apple TV Channel
Among UsAmong Us

The last five years (2021 to 2025)

Current, and all of it watchable now.

The Ark

2023–2026 · 3 seasons · Syfy
PhiloFandango at Home FreePlexNext episode 2026-09-16
AndorAndorHello Tomorrow!Hello Tomorrow!Star Trek: ProdigyStar Trek: ProdigyStar Wars: Tales of the EmpireStar Wars: Tales of the EmpireDoctor WhoDoctor WhoStar Wars: The Bad BatchStar Wars: The Bad BatchStar Trek: Strange New WorldsStar Trek: Strange New Worlds

Five to fifteen years back (2011 to 2020)

Recent enough that everyone can still find it, old enough to be finished.

Extant

2014–2015 · 2 seasons · CBS
Paramount Plus PremiumParamount Plus EssentialParamount Plus Apple TV Channel
Star Wars RebelsStar Wars RebelsMarsMarsStar Trek: Short TreksStar Trek: Short TreksStargate OriginsStargate OriginsMissionsMissionsLost in SpaceLost in SpaceStar Wars ResistanceStar Wars Resistance

Older than fifteen years (before 2011)

The back catalogue, where the closest match often is.

UFO

1970–1973 · 1 season · Associated Television
space
The Roku ChannelShout! Factory TVShout! Factory Amazon Channel
Lost in SpaceLost in SpaceDoctor WhoDoctor WhoStar TrekStar TrekEarth 2Earth 2Star Trek: EnterpriseStar Trek: EnterpriseCaptain Power and the Soldiers of the FutureCaptain Power and the Soldiers of the FutureBlake's 7Blake's 7

Want this tuned to you?

Name three shows you loved and it ranks the whole catalogue against your taste rather than against one title.

Build my list
Shows like Space: 1999 - Our Next Show