Originally Posted by Cormanthor

This guide agrees with Wowwiki's Spell Hit page. Here's another breakdown of the math:
26.232 hit rating = 1% hit at level 80. It requires at least 17% hit to never miss a raid boss (level 83 mob) with spells.

So for no buffs or talents (17% rating)	445.944 -> 446
With Draenei in party (16% rating)	419.712 -> 420
With 3 points in Suppression or Misery/IFF (14% rating)	367.248 -> 368
With Talents (or Misery/IFF) and Draenei (13% rating)	341.016 -> 342
W/ Talents & Misery/IFF (11% rating)	288.552 -> 289
With everything (10% rating)	262.320 -> 263