I'll second
Wing Shards. It's become a running joke in my group to ask what the storm count is, or if double white is up from how many times it's been a blowout. It got to the point where
Dispense Justice was a serious consideration for a couple decks.
Mirror Strike is quite good at reflecting commander damage if you encounter any 1-hit-wonder voltron decks, but even a sizable creature can make a day.
I've been trying out
Mandate of Peace as a 'fog' variant option, and have actually been quite happy with it. The secondary mode of shutting down follow up spells has really ruined some peoples hopes at recovering from the failed attack.
When it comes to wrath effects, I'm also a huge fan of
Rout as people don't typically expect you to wrath on their turn.
Tragic Arrogance also has some massive play potential, as you choose everyone's survivors.
My Linden and my Knights deck also both make decent use of the 3 mana indestructible spells. Ruining someone's attempt to clear your board is quite satisfying.
Flawless Maneuver is obviously the best, but
Unbreakable Formation and
Make a Stand are both quite good, as is
Rootborn Defenses.
I know you're asking particularly for mono-W, but in case you decide to explore this theme in other colors later, I just want to leave
Boros Fury-Shield,
Batwing Brume, and
Reflect Damage, all as having blowout potential.