Vast collections

• /r/chemicalreactiongifs
• EvilMadScientist.com — along the lines of MAKE
• Edward Kent's huge collection

Specific things I want to make

• thermic lance -- they can be made out of just about anything (bacon, cucumbers, spaghetti) and many can cut through metal, but the hottest ones can cut through 18" or more of solid steel. (details) (for impressive photos, search for "genuinely exhilarating")