My PCs like Eldritch Heritage (Arcane) to gain a familiar. You might encounter some table variation regarding whether you can qualify for Improved Familiar that way though if your PC also happens to have arcane caster levels either potential reading of the RAW is probably in your favor (nice for Bards or Sorcerers).
In one game where we all have cohorts I had my cohort take Eldritch Heritage (Destined) so he can give my PC a big 1 round boost of insight bonuses when the situation seems critical. There are some other interesting options for Eldritch Heritage, and of course there are also other uses for Skill Focus. For instance, one of my PCs took Skill Focus (Intimidate), which ends up being around as good as Intimidating Prowess at most levels but also allows me to get two other bonus Skill Focus feats. I chose Perception at 8th level and might take Stealth at 16th level depending on how things progress in that campaign.