What's your favourite cards for each character?

Not necessarily the strongest. Just the ones you really like.

Here's mine:

Ironclad — Ngl, I don't really play Ironclad a lot. Probably Whirlwind or Fiend fire.

Silent — Blade Dance, Blur, Eviscerate + Calculated Gamble and the whole discard package (Getting two really good discard decks is what finally made Silent click for me and I like her as much as Defect now), Burst, Malaise, maybe Catalyst?

Defect — Hologram, Defragment, Glacier, Biased Cognition, Electrodynamics, Echo Form, Seek, Fission+

Watcher — Tantrum, Flurry of Blows, Wallop, Carve Reality, Mental Fortress, Vault. (I'd like Rushdown if it was just once per turn. Entering wrath and getting more cards to turn your enemies into mulch feels good but it isn't very well balanced in its current state.)