Oh Hypno, Hypno, Hypno. What a pokemon you are. You are another one of those pokemon Gamefreak randomly dumped some good Special Defense onto, and then left. While Blissey and Jellicent are in OU thanks to this, you're stuck in NU, because you have nothing else good about you. You are nothing more than a gimmick Gamefreak wanted to implant in the early games; you can use Hypnosis to hypnotize your opponents into falling asleep, and have an ability preventing the same from happening to you. Problem is, Hypnosis has horrendous accuracy, and few other pokemon would really feel threatened enough to put you to sleep. Your Speed is mediocre at best, your offenses pathetic. Your move-pool isn't actually that bad (in fact, it's incredible!), and if there were more Fighting types in NU, I'm sure you would be popular. Alas, in a metagame where there are bigger and better Psychic types, some Ghost and Dark types, and almost no Fighting types, you are failing rather miserably. Even your abilities aren't that great. Frankly, you need better Attack or Special Attack to be good. It's sad that such a great move-pool is wasted on such a bad pokemon... TO THE ABILITIES!
Forewarn: Tells you your opponents strongest attack. Not really that great, considering it isn't that hard to figure out an opponent''s move set since they're all on Smogon. I guess it could give you a slight advantage. Moving on.
Insomnia: Prevents you from falling asleep. It's not bad, it just isn't that good either.
Inner Focus (DW) Prevents flinching. Again, not bad, but not good either.

Just saying, I'm not going to put an ability for these move sets, since they don't really affect the move set, regardless of what you pick.

Shnergreeerguerghashnmrglerrrg
-Nasty Plot
-Psychic
-Shadow Ball
-Focus Blast/Hidden Power [Fighting]
Item: Life Orb
Ability: Whichever
EVs and Nature: Modest (+Sp. Atk, -Atk)
252 Hp/252 Sp. Atk/4 Sp. Def
The title is the sound I imagine a Hypno making. Anyway, Nasty Plot is to boost your Sp. Atk to powerful levels. Psychic, Shadow Ball, and the Fighting attack of your choice all have perfect coverage between them. The reason I have tow Fighting moves is for Accuracy over Power with Hidden Power.

Glurggnshneergubumbrrrrrrr
-Drain Punch
-Zen Headbutt
-Ice Punch
-Thunderpunch
Item: Choice Band
Ability: Whichever
EVs and Nature: Adamant (+Atk, -Sp. Atk)
252 Hp/252 Atk/4 Sp. Def
It sucks that Hypno doesn't have Swords Dance or even Bulk Up, since his physical move-pool is amazing. But we'll make do with what we have. Drain Punch is "healing" and an overall good attack. Zen Headbutt is excellent STAB, and Ice Punch and Thunderpunch have perfect coverage offensively. Choice Band is so he can do some damage at least.

Other Options
Using Calm Mind to boost your Special Defense is always an option over Nasty Plot.
Baton Pass could be useful as well.
If you really want a support set, Toxic, Taunt, and Skill Swap are all options.
Meditate is not recommended, but can be used to boost your Attack if you want.

Partners
Dark types are generally a problem, so consider using Fighting types to aid Hypno. Ghost types can be a problem, so Dark types as well. Bug types are annoying, so bring in a Fire type. Altogether, we want Machoke with Payback and Fire Punch.

Countering Hypno
Absol utterly destroys him. STAB Sucker Punch of any kind, really, is fatal to Hypno, thanks to his lackluster Defense stat. Bug types sort of wall him. Any Special wall walls him, really. He isn't that great, but don't let it set up too much, or it will be a problem.