Without diverting to an esoteric discussion of what Evil actually is, no, the Aliens were not evil. At least they were no more evil than a nest of hornets or a pack of wolves.
Now, if you watched Pandora, you will appreciate that their origination may very well have been evil, although this supposes that we can understand the giant, bald Engineers who are willing to shatter their bodies with planet seeding DNA, but equally willing to exterminate their progeny.
Hal 9000 was certainly not evil. He was on a mission that in the end resulted in the Space Fetus and so what was the death of Gary Lockwood in comparison?
Were the Predators evil?
Yes indeed. Although technologically advanced beyond humans, there is no reason to believe that they exist on a different plane of consciousness from ours. They weren't out there hunting deer for meat, they were hunting sentient beings for pure sport and spinal column trophies.
Independence Day Aliens: Evil. Let's grant them the possibility that their species was desperate for a new homeland, having destroyed their own through obscene dependence on fossil fuels, they, clearly, could have come to Earth asking for help. If those damned xenophobic Republicans refuse their entreaty and tried to send a nuke up the main orifice of their Mother Ship...well, then maybe we can rationalize their destruction of the White House and the murder of the President's wife.
Mars Attack Martians: Evil...obviously. If yodels could kill them, they had to be evil.
Riddick? Good guy of course, although what alien race he is a member of is totally beyond me.
Individual Orcas, maybe, can be evil.
I love Orcas. They validate humans: They are very smart. They love their families. They kill. They eat meat. They play with their prey. Give them opposable thumbs and the ability to locute on hard ground and we humans may say goodbye to tomorrow.
Motive and the ability to choose are the determining factors in what is evil.
The Aliens motivation was survival and there is no reason to believe they had the capability of choosing between their furtherance and the end of another species.
The most horrific beasts whether in reality based fiction or sci-fi are those that can't really be described as evil, because they are utterly random and unavoidable, even for those who are willing to embrace evil to live. (Aliens- Jaws)
Which leads to an interesting discussion as respects serial killers, but let's save that for another thread.