Martian was amazing. It's a scientific fact, no point in arguing about it. The only recent Ridley Scott film that I'd recommend.
Speaking of, I'm shocked it's been 40 posts and no one mentioned Prometheus ;)

That wasn't really a bad movie, just a decent one.

Event Horizon has a great premise. A ship has passed over and come back ... and brought something with it? Great. But that movie sucks.

I liked The Sphere.

Decent ? Barely ok in my book. Great visuals and that's about it. Dumbass script, dumbass characters.
Or I'm just bitter and angry as I was expecting something as good as Aliens. Take your pick. (I think both are correct)

What are your thoughts on Covenant?

I liked Prometheus but yeah those characters were silly asf for scientists.

I have not seen it yet, because I heard people with a movie taste similar to mine criticize it in the same fashion they criticized Prometheus.
I was so disappointed by P... I don't know if I'll be able to survive Covenant ;)
Also, I missed it at the movies and am waiting for a good pirate.. I mean, a bluray release. Will probably watch it then ;)

Edit: and I have to address this. Scientists that act like they're ****in stoned all the time. A geologist with a huge set of sci fi tools used for mapping is the first one to get lost. A biologist who doesn't follow basic logic (let alone protocol). Oh, I also loved how our heroine managed to run around 40 seconds after a laser cut all her abdominal muscles in half, removing the alien baby from her stomach.. sure.
Generally I felt the movie originally was 2 hours longer and had to be cut down to be released, and the story and the plot suffered. There was no logic, no consistency, only plot devices. That's ok when we're talking about a college comedy or whatnot, but this was supposed to be "hardcore SF" right ? Well, baloney. Lazy writing, lazy editing, lazy lazy lazy.

You can nitpick both of them easily, but I loved both Prometheus and Covenant. I think they're interesting thematically, plus I don't find the characters as unbelievable as many others seem to. So what if a scientist gets excited over a weird alien creature and touches it. He's a human being, not a robot.

Terrible, terrible movie.

Great visuals? - check
Great premise? - check
Great cast? - check

It all tumbled downhill at 160 MPH after that.