In which episodes of Star Trek TNG were 'new life' encountered?

Question

This is not just a new species to the crew, but also new to the viewer. I remember in TNG that there were several new aliens; Q, Nagilum, etc.

What other "aliens" did the crew encounter? This would be anything that was a creature who was sentient, another lifeform which had to interact in some way with a character, that might have displayed an ability or an influence or something that says "Hey, I could be a threat!"

Hallucinations or the crew being transformed into things don't count.

I'm especially interested in species where communication between the lifeform and the crew was possible or if the lifeform was otherwise a threat

Answer 1

Taking into account only those episodes where the crew of the Enterprise-D encounter a wholly new lifeform or uncover one that was previously hidden, the crew succeed in their mission to "seek out new life" on no less than 37 occasions.

_{Where the species is sentient, they're marked with an (s). Where they're malevolent, they're marked with a (m)}

Season 1

Encounter at Farpoint, Part I: The Q (m)(s)
Encounter at Farpoint, Part II: Two unnamed warp-capable jellyfish (s)
Lonely Among Us: Unnamed energy lifeform (s)
Justice: The Edo(s) and their unnamed god (s)
Datalore: The Crystalline Entity (m)(s)
When The Bough Breaks: The Aldeans (s)
Home Soil: Unnamed Silicon-based lifeform (s)
Skin of Evil: Armus (m)(s)
Conspiracy: Unnamed Parasitic lifeform (m)

Season 2

The Child: Unnamed energy lifeform (s)
Where Silence Has Lease: Nagilum (m)(s)
Pen Pals: The Dremans (s)
Q Who: The Borg (m)(s)
Shades of Gray: Unnamed Alien Parasite (m)

Season 3

Evolution: Wesley's Nanites (s)
Deja Q: The Calamarain (m)(s)
Allegiance: Unnamed impersonating aliens (m)(s)
Tin Man: Tin Man/Gomtuu (s)

Season 4

Future Imperfect: Unnamed species/Barash (s)
The Loss: Unnamed Two-dimensional space-faring species
Clues: The Paxans (s)
Galaxy's Child: Unnamed Space-whale
Identity Crisis: Unnamed DNA parasite (m)
The Nth Degree: The Cytherians (s)

Season 5

Darmok: Unnamed El-Adrel Beast (m)
Power Play: Unnamed electromagnetic entities (m)(s)
Imaginary Friend: Unnamed energy lifeform (s)
Time's Arrow, Part I: The Devidians (m)(s)

Season 6

Realm of Fear: Unnamed Subspace microbes
Schisms: Unnamed Solanogen-based lifeforms (m)(s)
Aquiel: Unnamed shape-shifting predator (m)(s)
Timescape: Unnamed quantum singularity aliens (s)

Season 7

Liaisons: The Lyaraans (s)
Interface: Unnamed subspace creature (s)
Sub Rosa: Unnamed energy lifeform (m)(s)
Emergence: Unnamed Vertion-based lifeform