I had a ride in a sidecar once, it was neat , but weird. I understand driving a sidecar rig takes some learnig, but driving my trike only took learning to be confident that I couldn't tip it over! (You could say I tried to) it isn't your average trike, and I did have to learn to shift an H - pattern under my left thigh, but that was easy enough.
So my vote is trike, but then I'm biased and still have two-wheelers too.