Heeyyy, I did not expect that to blow up like this! Thanks for all the recommendations.

Here is a summary of the mentioned books / series (in case someone is also searching for a new good book)

• Starship’s Mage series by Glynn Stewart
• Larry Niven’s Flatlander
• Red Rising saga by Pierce Brown’s
• The Expanse
• Clarke’s Rendezvous with Rama
• The Bobbiverse Series
• Children of Time/Ruin/Memory/Strife - Adrian Tchaikovsky
• Kim Stanley Robinson’s Mars (other books from the same autor are Aurora and 2312)
• Peter F Hamilton: Nights Dawn Trilogy
• Ian M Banks: Culture Series
• The Void Trilogy
• Hitchhikers Guide to the Galaxy
• Teixcalaan duology by Arkady Martine
• Gideon the ninth
• Becky Chambers’ Wayfarer
• Redshirts by John Scalzi
• The Mote in God’s Eye
• CJ Cherryh’s Foreigner series and Alliance-Union universe
• Neal Asher’s Agent Cormac series
• Nnendi Okorafor’s Binti
• Expeditionary Force by Craig Alanson
• 2001: A Space Odyssey
• The Interdependency Serie
• Foundation from Isaac Asimov
• The Inverted Frontier series by Linda Nagata
• Project Hail Mary
• Dan Moren’s Galactic Cold War
• Alan Dean Foster: The Damned Seies
• Little Fuzzy - Fuzzy Sapiens - Fuzzies and Other People
• The Man Who Never Missed - Matadora - The Machiavelli Interface
• The Ancillary serie