Hmm, let's see.
- Since TNG wasn't an action-oriented series, D got into relatively few scrapes and in those it oft dominated or got dominated quickly. Then there's its obliteration in Generations.
- A wasn't really confronted with long battles either.
- The Defiant survived many battles, some of which proved deadly to might Galaxy-class ships, but it usually did so through alacrity and raw firepower, not resilience.
- Voyager's main trick was its near-endless supply of reset buttons, nothing to do with the ship itself.
- NX sure took a lot of abuse in the Xindi arc.
- E was partly assimilated and used to ram a powerhouse... and live to tell the tale.
So, I'd say: E>NX>Defiant>D>A>Voyager in terms of defensive capability.
actually you are quite mistaken about voyager reset buttons has nothing to do with the amount of damage the ship took.
the Intrepid class itself seems a very defensive ship,from the beating it took in year of hell to the confrontation with the Tactical cube in unimatrix 0,it proved it has far more resilience/Defense in combat then the D/NX/Defiant easily. only ship that actually might beat it in that department is ENt-E,on screen evidence clearly proves it.