What good spells qualify for the new twinned spell meta?

I have only see charm person and hold person I think that would maybe be decent. Any other ideas?

1. Charm Person, Chromatic Orb (each person can only be targeted once, I'd allow it), Jump, Magic Missile (get extra missiles that you can use on extra targets, again I'd let it go)
2. Blindness/Deafness, Enhance Ability, Hold Person, Invisibility, Scorching Ray (get extra missiles that you can use on extra targets, again I'd let it go), Spider Climb
3. Fly, Gaseous Form
4. Banishment, Charm monster, 
5. Hold Monster
6. --
7. --
8. --
9. (technically any such spell from any list of levels 1-8, eg Longstrider)

Note - I've upcast the bolded ones as a wizard for the extra creature effect, so I'd say useful.

Quote from Estaln >>

1. Charm Person, Chromatic Orb (each person can only be targeted once, I'd allow it), Jump, Magic Missile (get extra missiles that you can use on extra targets, again I'd let it go)
2. Blindness/Deafness, Enhance Ability, Hold Person, Invisibility, Scorching Ray (get extra missiles that you can use on extra targets, again I'd let it go), Spider Climb
3. Fly, Gaseous Form
4. Banishment, Charm monster, 
5. Hold Monster
6. --
7. --
8. --
9. (technically any such spell from any list of levels 1-8, eg Longstrider)

Note - I've upcast the bolded ones as a wizard for the extra creature effect, so I'd say useful.

One might also consider the level 6 spell Chain Lightning, which I think is fair to allow if you allow Chromatic Orb.

If you're willing to dip back into 5e spells that haven't been updated, there's also Catnap from Xanathar's Guide to Everything and Intellect Fortress from Tasha's Cauldron of Everything. Both of these are fairly situational, but when you need 'em, you really need 'em.

Quote from wagnarokkr >>

Quote from Estaln >>

1. Charm Person, Chromatic Orb (each person can only be targeted once, I'd allow it), Jump, Magic Missile (get extra missiles that you can use on extra targets, again I'd let it go)
2. Blindness/Deafness, Enhance Ability, Hold Person, Invisibility, Scorching Ray (get extra missiles that you can use on extra targets, again I'd let it go), Spider Climb
3. Fly, Gaseous Form
4. Banishment, Charm monster, 
5. Hold Monster
6. --
7. --
8. --
9. (technically any such spell from any list of levels 1-8, eg Longstrider)

Note - I've upcast the bolded ones as a wizard for the extra creature effect, so I'd say useful.

One might also consider the level 6 spell Chain Lightning, which I think is fair to allow if you allow Chromatic Orb.

If you're willing to dip back into 5e spells that haven't been updated, there's also Catnap from Xanathar's Guide to Everything and Intellect Fortress from Tasha's Cauldron of Everything. Both of these are fairly situational, but when you need 'em, you really need 'em.

 Chain lightning shouldn't even be in question. It just straight-up fits.

There's also Tasha's Mind Whip.

Yeah, I would agree that Chain Lightning is clearly allowed, I just remember getting into a stupid argument with someone about it at some point. I don't even remember what their argument against it was.

And Tasha's Mind Whip seems like a great choice due to the debuffs it applies.

I had a 2 min scan on the PHB only, but yeah plain missed chain lightning - lol

Does the spell say "You can target one additional creature for each spell slot level above X." Then you can twin it.

Adding additional effects that might target others doesn't work.  The language is clear and identical for twin.  

Quote from Taenx >>

Does the spell say "You can target one additional creature for each spell slot level above X." Then you can twin it.

Adding additional effects that might target others doesn't work.  The language is clear and identical for twin.  

This has been debated quite a lot, but I do just want to point out that what it actually says is that it applies to spells "that can be cast with a higher-level spell slot to target an additional creature".

The idea that this means it only applies to spells that say specifically "You can target one additional creature for each spell slot level above X." in their description is one that some people seem to feel very strongly about, but the rules do not actually say that anywhere, so many people do not play with such a restrictive interpretation.