Gale because he is useful, funny and his story seems interesting. I would never romance him even he is really looking for it. (What an old pervert)
Laezel in second because she is a very efficient fighter and I think there is a chance that she can become a trustfull ally that if she may be disappointed by the way of Vlaakith.
I hate vampires so bad luck with Astarion. I generally kill him directly.
I generally kill Shadowheart on the beach to get the artefact. It is quite obvious she is a Shar priestess (by the armour, by the fact this is indicated into the character sheet ...) so letting a powerful artifact with a neutral evil agent, no way.
Wyll is so weak at low level and entrust a devil so even if neutral good, I will not use him.
In a general way, from I have seen so far, it is difficult to build different efficient packs due to directions taken by the origins characters. The best so far was Gale, Laezel & Wyll...
I am currently trying a pack with Gale, Shadowheart & Astarion + my character as priest oh Shar and it is really not working well. Laezel + Shadowheart is too much complicated to manage.
I hope to be able to create my own party easily and I will perhaps take either Gale or Laezel. It is a pity because I am pretty sure a lot of work has been done on others origins characters but it just doesn't match with me.