Comic Book Superhero Birthday Party- thank you favor tags by A Party Studio on Etsy, only $7.00
Cute treasure hunt ideas. Adults could have fun being creative (finding a full moon, etc!). Could have couples take pics of items on a cell phone, or have guests bring creative versions (for ogre nails and vampire teeth, etc) to add to a "spell" at a witch-themed party (maybe once all ingredients are added to a pot, a surprise is revealed...?)
Adult Surprise Party Invitation Printable, 40th Birthday, 50th Birthday, 60th Birthday Typography Subway Vintage. $16.00, via Etsy.
Cool guy birthday party idea: Scotch and chocolate...yum.