Party Considerations

[Helspanth]

I have the following party.
Me-fighter
Mazzy
Tashia-the NPC add on a sorceress
Cend
Jan
Who do you think it would be good to add?
I plan to keep all those NPCs since I've never completed the game so please I don't need any "drop Cernd,he sux".The same goes for all the other NPCs.

[Dundee Slaytern]

You lack a Cleric, so consider getting Anomen. Just remember to do his subquest ASAP to preserve your nerves. His banter with Jan Jansen is hilarious too.

[Ar-Cunin]

I would say get Aerie

Together with Cernd you'll have enough cleric spells, and she'll give you good mage backup (and experience from reading scrolls)

[Sir Exxon]

I agree with Dundee here. Anomen should be a good addition to the party, giving you both a new tank, and a priest.

[Gothmog, Lord of Balrogs]

Cernd, Tashia, and Jan give you plenty of spells, and a cleric isn't really necessary, unless you want one. (it helps when Cernd is a wolf and can't cast spells) If so, get either Anomen or Viconia, whatever you want. I have heard that Viconia can be turned Good in ToB, and it gives you a romance option, too. Since you seem to be playing neutral, either of them is fine. However, if you want a pure tank, go with either Valygar or Minsc. Everything is your choice, and you should never rule out Keldorn and his Holy Avenger as an option.

[Albromor]

Cernd isn't all that great. I'd go with Jaheira if you want a Druid, plus she is a Fighter. If you also add Aerie you'll get both Mage and Cleric spells. Personally, I think the multiclass cleric/mage is one of the best support classes in the entire game.
Clerics, IMO, are essential in BG2, so if you got Anomen it would be a definite plus, but don't be surprised if you join the legions of "I Hate Anomen" club. As someone already said, do his quest as soon as possible and he'll be much more tolerable. Prior he is insuffarable. The thing about BG2 is that there are many combinations you can try. There is no one right party. For what it is worth here is my party:

Me - Half-elven Fighter/Mage
Minsc
Yoshima - I'll use him and then drop him for Keldorn.
Jaheira - Fighter/Druid, but she can heal and has useful spells
Nalia - not great Thieving skills, but a really good mage; may drop her for Jan
Aerie - like I said, love the multiclass cleric/mage

* The thing is I am not done tinkering. There will be changes to
come.

[Witchhunter]

Anomen is a good choice he is usable as both fighter and cleric, although I find his personality utterly annoying. Minsc is a good fighter and he got a good personality to boot. Korgan is evil but is propably the best fighter in the entire game. Keldorn with Carsomyr is a killing machine(especially if you give him Gloves of Ogre Power or some other Strength boost). The same go for Valyagar.

[Maxamus]

My Good Party:

Me - Archer
Minsc - used as tank
Jaheria - Good field medic with fighter abilites
Nalia - Last choice Medic, and supprt mage
Yoshimo - For my thieving Needs
Jan or Mazzy - there special skills coem in hadny

Evil Party

Me - Sorcerer, Beefed up with SK cause theres limtied evil options
Keldorn- Tank
Yoshimo - Thieving needs
Viconia - Clerical Support

and sometimes Edwin if I feel like i want more magic options, but currently my beefed up sorcerrer is good enough

[Helspanth]

Ok so I'm between Anomen,Jaheira and Valygar.
Who is the best option?

[Dundee Slaytern]

No point having Jaheira in your group. Having two Druids in a party is overkill.

I would choose Anomen because you lack a Cleric. Cernd is not a Cleric, he does not have access to Clerical spells like Chaotic Commands.

Valgar is a good tank, but so is Anomen. Especially after you cast all the good Clerical spells on him.

PS: I am assuming you are using Mazzy as an Archer.