B10 Night's Dark Terror! Queued for immediately download. I reference the Expert rules quite a bit, it's fantastic to have a bookmarked, searchable version. I'm really happy with the scan of B10 - they did an excellent job converting it to a nice looking, useable PDF. The original had many oversized maps and double-sized maps, making it problematic on previous scans. I didn't look for a definitive list of new items, but I don’t remember seeing T1-4 Temple of Elemental Evil last time; that looks new as well.
B10 Night's Dark Terror is a phenomenal adventure; if you missed it back in the day, now's your chance. I'll pen a brief review later, after the nerd-buzz calms down. I'd still love to see the Creature Crucible series added; the Mystaran Gazetteers; 2E Ravenloft and some of the Ravenloft adventures; and 1E Gamma World added to the catalog, but now I'm glad to wait.