This sequel to the 1994 movie Stargate chronicles the further adventures of the Stargate Command. It turned out that the Goa'uld Ra was only one of many alien System Lords who used the Stargates to conquer much of the universe. When Earth uncovers a working cartouche to decipher the coding system of Earth's stargate, they can now travel anywhere. Earth's military sends out SG teams to explore new planets, find technology, and oppose the Goa'uld. Jack O'Neill and Daniel Jackson from the movie are part of SG-1. They are joined by Sam Carter, a scientist, and Teal'c, a Jaffa who is convinced the Goa'uld are not gods.
The Martian Chronicles by Ray Bradbury
Leaving behind a world on the brink of destruction, man came to the Red planet and found the Martians waiting, dreamlike. Seeking the promise of a new beginning, man brought with him his oldest fears and his deepest desires. Man conquered Mars—and in that instant, Mars conquered him. The strange new world with its ancient, dying race and vast, red-gold deserts cast a spell on him, settled into his dreams, and changed him forever. Here are the captivating chronicles of man and Mars—the modern classic by the peerless Ray Bradbury
The Host by Stephenie Myer
Melanie Stryder refuses to fade away. Our world has been invaded by an unseen enemy. Humans become hosts for these invaders, their minds taken over while their bodies remain intact and continue their lives apparently unchanged. Most of humanity has succumbed.
When Melanie, one of the few remaining "wild" humans, is captured, she is certain it is her end. Wanderer, the invading "soul" who has been given Melanie's body, was warned about the challenges of living inside a human: the overwhelming emotions, the glut of senses, the too-vivid memories. But there was one difficulty Wanderer didn't expect: the former tenant of her body refusing to relinquish possession of her mind.
Wanderer probes Melanie's thoughts, hoping to discover the whereabouts of the remaining human resistance. Instead, Melanie fills Wanderer's mind with visions of the man Melanie loves - Jared, a human who still lives in hiding. Unable to separate herself from her body's desires, Wanderer begins to yearn for a man she has been tasked with exposing. When outside forces make Wanderer and Melanie unwilling allies, they set off on a dangerous and uncertain search for the man they both love.
Gateway by Frederik Pohl
Gateway opened on all the wealth of the Universe...and on reaches of unimaginable horror. When prospector Bob Broadhead went out to Gateway on the Heechee spacecraft, he decided he would know which was the right mission to make him his fortune. Three missions later, now famous and permanently rich, Robinette Broadhead has to face what happened to him and what he is...in a journey into himself as perilous and even more horrifying than the nightmare trip through the interstellar void that he drove himself to take!
Gates of Ivrel (Morgaine series) by C.J. Cherryh
Scattered about the galaxy were the time-space Gates of a vanished but not forgotten alien race. In their time, long before the rise of the native civilizations, they had terrorized a hundred worlds—not from villainy but from folly, from tampering with the strands that held a universe together. Now the task was to uproot these Gates, destroy their potency for mischief, take horror out of the hands of the few who hungered for power by misuse of the Gates. This is the story of one such Gate and one such world.
There’s also a tie-in series with almost twenty books that might be worth looking into, but I’m wary of those because it can be hit or miss with characterization.