A 40 (Addendum)
Originally Posted by Narse
I think that would be reincarnate, available at level 7 for a Druid, but I may be mistaken.
Reincarnate has a casting time of 10 minutes.
Off of the top of my head there are a few spells with a casting time 1 standard action which could be used to immediately
revive someone who died the previous round.
1) Revivify. It's a 5th level cleric-only spell, so you would need to be at least level 9 to cast it. It brings the target back to live with -1 HP and no level loss, and costs only 1,000 gp in material components. However, it must
be cast within one round
of the target's death.
2) Last Breath. 4th level druid spell (minimum character level 7). The creature returns to life with 0 hp, loses a level or a hit die (or 1 con, if it's level 1), and has a 50% chance of losing prepared spells or unused spell slots. Like Revivify, this one must be cast within one round of the target's death. This spell has no material component cost
3) Revenance. This one's available as a 4th level cleric spell (minimum character level 7). It brings the target back to life with half of its full HP, no level loss, costs no material components, and the subject gains a +1 morale bonus to all attacks, damage, saving throws, and checks against the creature that killed him. The window of opportunity on this one is a bit larger than than the other two (up to 1 round per level after the target's death).
The catch on Revenance is that it has a duration of 1 minute per caster level, after which the subject dies again. It's particularly fun to leave that last detail out when casting the spell on someone who is not familiar with it.
Note: All of these spells restore the target to life in whatever condition its body is in, like Raise Dead. Missing limbs are not regenerated, and you probably won't be able to cast the spell at all if the the body is too badly damaged.