Best bloodline for a illusionist sorrcer

[JOHNB83]

Title says it all any tips.

[XMorsX]

Undead probably, so that you can affect undead. Serpent comes second, less useful arcana but more well-rounded bloodline IMO.

Of course, you cannot go wrong if you choose the Arcane bloodline, even if there is no special synergy (other than the eventual increase in your school DC).

[Inlaa]

I second the Undead suggestion. A player in my game played a crossblooded sorcerer with Undead as one of his bloodlines. I was so angry when my ghouls that were about to paralyze him got color sprayed in the face.

[Quandary]

Rakshasa's Arcana boost to DC to Spellcraft ID your spells could be relevant if your opponents aren't meant to know you are casting Illusion spells... I believe opponents get some sort of bonus or an extra/automatic Save to Disbelieve if they have good reason to think it is an Illusion, i.e. because they ID'd it as being of the Illusion school (only relevant for certain types of Illusions). AFAIK there are some other options (Feats?) to do the same, either stacking with Rakshasa for maximal reliability or helping out non-Rakshasa builds.

Arcane is a good one if you consider going Cross-Blooded, because it's bonus Spells Known partially offsets the downside of Crossblooded. Crosssblooded's Will Save penalty also hurts though.