(Dug around for this a bit but didn't seen anything specific, pardon if I missed it.)
Basically as title. Any attack, heal, or passive you found particularly effective, helpful, or just plain cool? It can be from Class, Weapon, whatever.
My favorite so far is Silver Bolts, which you get for Rank 2 in Fighters Guild. Since my Breton Templar is to this point (level 13) melee-range only, it's nice to get a ranged attack, but that's just scratching the surface.
1) It's very nice against Undead and Daedra. You'll be seeing a lot of both. Knockdown is quite useful.
2) Damage is decent no matter what you're fighting.
3) At 5% chance you won't see it a lot obviously, but when it goes off, that huge bonus damage is jaw-dropping. I've seen it go off twice, against an Imp and a Zombie. Both instant-kills, and the Zombie simply exploded into ash. Holy crap.
4) The animation looks really sweet. You whip out a hand crossbow.
Definitely my favorite attack so far. I use it every fight against everything, while running into melee. I haven't morphed it yet, the grab-and-yank one sounds more everyday useful, but the added AoE sounds really nice during a Dark Anchor.