Fainting Goat Games has a series called Improbable Tales that feature a wide variety of superhero adventures that are all under $3 (they have a bundle, too). My current fave is Helicarrier Heist, because that sounds like either a great one shot, or something that you could either kick off a campaign with or easily splice it in.
The initial run of short adventures for Golden Heroes published in White Dwarf was pretty much all gold too. The first issue I ever got (67 in the original numbering) included "Peking Duck" by Phil Masters, in which the PCs are one of at least three sides of a chaotic super-brawl in the confines of a busy restaurant. Issue 73 featured "The American Dream" by Simon Burley, a highly ambitious adventure which included an army of twenty low-level supers as one encounter even though it only ran for six pages.
Grande Nuit La for french rpg Brigade Chimerique has 191 pages with 10 scenarios in which the PCs must save the world from the future apocalypse with the help of a cryptic time traveller. Apparently its very highly regarded as a supers rpg campaign with the best part at the end.
Larry DiTillio, co-author of Masks of Nyarlathothep, one of the best RPG campaigns ever written, has passed. In addition to his role-playing work, Larry was also the author of the story bible for he-Man and the Masters of the Universe, and the executive story editor for Babylon 5. The thread on his loss can be found here.