I might also revive the Anime Multiverse teased in BESM 3e. Mostly because I got really excited about it for some reason, and then Guardians of Order folded.
Ooh, that reminds me! Reve: the Dream Ouroboros (or Dragon, these days, but that's more prosaic). Whimsical French Alice in Wonderland surrealism meets high fantasy. Rerelease with a lighter system (but keep the hexmap-based magic system, that looked so cool).
That was largely what I came here to say.Everway for me. Rerelease the Spherewalker's sourcebook, release a bunch of sumptuous sets of cards related to my favourite settings (Nobilis, Chuubo's, Tekumel), probably via Kickstarter, then release the whole thing as an app with story generation tools for a reasonable price some time later.