If you like "Threshold", then you might enjoy...

FBI agent Olivia Dunham teams up with a formerly institutionalized scientist Dr. Walter Bishop and his son Peter Bishop to investigate weird crimes. Crimes that are part of a larger pattern.

Dr. Walter Bishop`s knowledge of fringe science that he worked on before he got institutionalized comes in handy when the team faces a rapidly spreading series of unexplained phenomena.

Fringe is a really good science fiction crime show. They get into so many cool and crazy incidents while working on their cases. They try to explain it in a scientific way, as much as it is possible.

Fringe is not about aliens and it has more paranormal elements. It does have scientists as a central element, but its more paranormal and science fiction science.

Fringe is a good show worth watching. It's not too similar to Threshold, but you will probably like it.

Falling Skies starts in the aftermath of an alien attack. An attack that has left most of the world completely incapacitated.

Humanity has for the most part lost.

The few remaining survivors have banded together in a last desperate attempt to survive.

Each day is a test of survival as they work to protect against the occupying alien force, whose purpose remains a mystery.

Falling Skies is also about an alien invasion. It has less mystery and more action than Threshold.

If you like Threshold and want something more post-apocalyptic and full of action, then Falling Skies is a good show to watch.

For centuries, humans have searched the skies for signs of intelligent life, to no avail.

But what if the aliens were already here, already among us?

And what if all of the natural disasters were smokescreens created to mask something far more ominous?

For dedicated U.S. Park Ranger Russell Varon, a devastating Florida hurricane and its mysterious aftermath proves to be merely the beginning of a long journey into the unknown.

Invasion is among the better sci-fi shows I have seen.

Too bad it lasted for such a short time.

Invasion has a disease that spreads around and takeover people.

It's very good and feels similar to Threshold in many ways. It has more of a local scale on the story, but it still feels very similar. And its a very good show.

Aliens have come among us, and they aper to want peace and to share their knowledge with us.

After some initial uncertainty, they have now become accepted. People have started to work for them and promote them to others.

Agent Erica Evans, working in the counter-terrorism division in the FBI, discovers what hidden beneath the human exterior of the aliens. And it is not pretty.

V was a fantastic show that I truly miss.

I wish it had lasted longer.

V also has an alien invasion as the main theme. They look like humans, but they do not take over human bodies. V has more dishonesty, tricker, and action in it.

If you like Threshold then you might like V.

A new form of sea life is discovered. It is found in multiple places around the globe at the same time.

Initially, it is beautiful and playful, but what no one knows is that we are on the verge of a world disaster.

Surface is a great show with good acting and excellent effects for its time. The story is also good.

I love this show. The only downside is that it ends too early and on a cliffhanger. I hate when studios disrespect their fans like this.

A new species is found that might threaten human existence. It might not be alien, but it's new and mysterious.

Surface is a very good show and is have many similarities to Threshold, even if it might not involve aliens.

The year is 2046 and over 30 years have passed since the aliens arrived.

They drastically altered earth by terraforming it and colonizing it.

In the frontier town of Defiance, the different alien species and humans are living side by side.

This, of course, is not without tension between the different spices. It makes for a lot of small, and not so small, problems to overcome.

Defiance is also about an alien invasion, but it is set long after in a post-apocalyptic earth.

If you like Threshold and want something post-apocalyptic and full of action then Defiance is worth watching.

Dr. Ephraim Goodweather is the head of the Center for Disease Control Canary Team in New York City.

Eph and his team are called upon to investigate a mysterious viral outbreak with an uncanny similarity to vampirism.

With help from a mysterious Holocaust survivor, Eph and his colleagues has to stop this disease from wiping out mankind. They do this by attacking its source, a sinister supernatural creature known as The Master.

I like this show, but it could have been so much better. It differs too much from the books.

Both shows have a pandemic virus that infects people with the intent to take them over.

Brought together to form one extraordinary team of "Alphas" - people whose unique brain anomalies imbue them with superhuman mental and physical abilities – five seemingly ordinary citizens must take the law into their own hands while working within the government to investigate a new brand of baffling crime. - Amazon

Alphas is an excellent series, but I am not sure if I should recommend it. There is one thing that I hate with this series, and that one thing is the reason why I will never buy this show. They canceled it with a cliff hanger. That should be a criminal offense, an offense punished by no TV for the rest of their life.

4,400 people that have gone missing over a period of 60 years is suddenly returned. They return from a big ball of light originating from outer space.

The government collects all of them up in a facility until they understand what is going on.

Federal agents on the case slowly discover that the victims have been changed.

They have gotten special powers.

This is a good show, absolutely worth watching.

But be warned, this show got canceled without a proper ending. The producers truly screwed us over by ending it as they did.

Captain Jack Harkness is a former Time Agent and con man from the 51st century.

He was last seen traveling with the Doctor on an adventure to early 21st century Cardiff.

There, he becomes a member of the Torchwood Institute. Its a renegade criminal investigation group founded by Queen Victoria. Their goal is to battle hostile extraterrestrial and supernatural threats.

Whales begin sinking ships. The North Sea shelf collapses, killing thousands in Europe.

Around the world, countries are beginning to feel the effects of the ocean's revenge.

The seas and their inhabitants begin a violent revolution against mankind.

Parasitic aliens descend upon Earth. They quickly infiltrated humanity by burrowing into the brains of sleeping people.

The take control over the humans they burrow into. They can also shapeshift into horrendous shapes to fight and eat humans.

Shinichi Izumi is a sizteen-year-old highschool student, and he fell victim to one of these parasites. But it failed and it had to settle for taking his arm instead.

The parasite called Migi and its host Izumi has to learn to live together. They have to learn to go about daily life and to fight other parasites.