I never look at the VA cast for new shows either. I tend to see recognizing a voice within a show as more of a distraction than anything else. If the voice is very strongly identifiable I often start blending the characters in my mind which can mess up the immersion experience. I notice this especially with whoever voiced Zetsubou Sensei. Pretty much anytime that guy yells in any show I think about his triple-take schtick from SZS.

If I do manage to recognize a voice but not where I've heard if from I usually go look it up to see what other roles I might have heard it in but after the first time I generally forget pretty quickly and don't care the next time I realize I've heard the voice before.