I am not terribly serious yet, and I won't be until I'm convinced I'm ready to push a project all the way through completion. However, I tend to have two general sorts of ideas about an aircraft that don't tend to drift too much:
-LSA that can carry two heavy people, good handling and moderate stall speed as I'd be a low time pilot, oddball but appealing (to me) appearance, enclosed cockpit. range and speed not terribly important. prefer something with a safe history, shortest possible build time but not sure I'd want a kit. A Davis 2A with larger would fit the bill but I doubt if such exists. Or a Volksplane 2 with a cabin and more oomph. But I don't actually know what the simplest, fastest to build aircraft are. If I was designing it myself it might end up like a 2 place Facetmobile. Might make more sense to get old 2 place spam can. Ugh!
-part 103 compliant motorglider, probably would have to be a new design, would need to be generous in structural strength, medium performance, say 25:1, 150fpm or less sink rate, 100 would be nicer. Not sure what scheme to have adequate power and not bust the speed limit. Would need to be 4 stroke or electric. 2-strokes are dirty and noisy, and probably I'd mess up and lose an engine at a bad time. Probably flapped to meet 103 better, maybe Strojnic style wing, though light skins that didn't shred with hangar rash might be a problem. Fantasy would be Horten style flying wing, normal configuration probably much easier to design.
Of course a blend of above might be very nice, but realistically a Xenos would be better for that mission, if much more expensive than I'd want to contemplate. Other thought was that one could make a low aspect ratio, "smoothmobile" delta flying wing with motor for launch and at least hang glider performance (say 12:1 or better and very light loading)