fur coat: doubles defense
Multiscale/ Shadow sheild- any moves that hit you while you're a full health deal halved damage
Stamina: obvious
Marvel scale: your defense is doubled is you have a serious status condition
Shell armor: One of several, prevents crits
Bulletproof: prevents "ballistic" moves (I have limited info on what these moves are, but I know Shadow Ball and Aura sphere from experience).
there are also several different abilities that completely blot out an entire type from having any effect. these include:
Motor Drive/ Lightning rod- heals/ raises sp. atk if hit by electric type move
flash fire- raises power of fire type moves if hit by one, but only the first one. Any other fire attacks will have no effect whatsoever
water absorb/ storm drain- heals/ raises sp. atk. if hit by a water type move
sap sipper- raises atk. if hit by a grass type move.
There are probably more, but these are all I could think of when I wrote this.