After Rebirth, Mrs. He Dotes On Her Husband - Chapter 492 - : Caught

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

The life story of Gun Choi going towards being the best pitcher in the baseball Major League.

From [Running], to the physics-defying [Godspeed].From [Aiming], to the causality-transcending [Bullseye].From [Health Cultivation], to the everlasting [Immortality] among men.From [Fitness], to the flesh-ascending [Turning into a Dragon].Having been reborn, Xue Jing, after gaining a panel that infinitely enhances skills, set a minor goal for himself.In this dangerous world filled with martial artists, Blessed Ones, and Transformed People, he aimed to rise above all merely with his mortal flesh and blood—to become the supreme deity among men.

“O, Hero!” With that cliched line, Kazuya Souma found himself summoned to another world and his adventure–-did not begin. After he presents his plan to strengthen the country economically and militarily, the king cedes the throne to him and Souma finds himself saddled with ruling the nation! What’s more, he’s betrothed to the king’s daughter now…?! In order to get the country back on its feet, Souma calls the wise, the talented, and the gifted to his side. Five people gather before the newly crowned Souma. Just what are the many talents and abilities they possess…?! What path will his outlook as a realist take Souma and the people of his country down? A revolutionary transferred-to-another-world administrative fantasy series starts here!