It'd be nice to have some kind of FOSS business suite, aka point of sale, accounting, inventory etc. I'm not a fan of Intuit.
I've also not found journal software I really like. RedNotebook is about the closest. I tend to use my journal not only as a personal diary but also as a place to brainstorm and I would also like a checklist/to-do list system, and this I haven't found in any software free or proprietary. I may have to build it myself, with my rudimentary knowledge of qt.