I've had to deal with a couple on the maintenance side, one was in flight & the other on the ground. Both cost big bucks!
The one in flight was a Cessna Caravan - everything steel ended up magnetized & had to be degaussed, a bunch of flight control bolts had arcing damage & it lost some sheet metal on one elevator where the bolt exited (and most bonding wires got cooked along the way). It was hit on the prop - both the prop & the engine had to be replaced, the engine because it was magnetized & also suffered a partial power loss after the strike.
The one on the ground was a CH-47 - an aft rotor blade was struck, these are composite with an embedded wire mesh for lighting strike protection & bonding wires running to the rotor head. Blade was toast (the wire mesh cooked it's way out of the blade) along with the head, can't remember if the transmission was hurt or not - the bonding wires between the blade & rotor head vaporized. The aircraft was connected to a ground point on the ramp & the wire melted, along with a ground wire that hangs off the aft landing gear & contacts the ground.