Grand Unifying Guesses/Girl Genius

The following characters/people are Sparks.

 * Tony Stark
 * Adam Savage and Jamie Hyneman
 * Leonard de Quirm
 * The Mechanist
 * Foaly, Opal Koboi, and quite possibly Artemis himself
 * Dr Henry Jekyll (of a more Mad Chemist variety)
 * Cave Johnson (come on, he created a device that connects two points in space with a wormhole - while attempting to design a shower curtain)
 * He just took after his ancestor, B.S. Johnson.
 * That made so much sense...
 * Wallace
 * Professor Isaac Sumdac.
 * Kat Donlan.
 * Kaolla Su
 * Dr. Bunsen Honeydew. Poor old Beaker has classic Minion syndrome.
 * Kim Possible: Dr. Drakken, Wade, and possibly Ron (based on his evil side), and Kim's little brothers. Kim is currently channelling her Spark in more athletic ways, but when she breaks through, she'll make her foes look like amateurs.
 * The Doctor, and also The Master.
 * Lelouch, whose capabilities with planning are borderline precognitive.
 * Nikola Tesla
 * Phineas
 * Doctor Octopus
 * Mordin Solus
 * Doctor Robotnik
 * Willy Wonka. Nuff said.
 * Doctor Horrible
 * Tedd Verres. Obviously.