“A journey of a hundred light-years begins with a single step.”
~ Confucius (extend 12 orders of magnitude)
There is no single "best" starship concept. Although many researchers have their favorite, the "best" depends on one's perception and motives. Often these priorities go unmentioned as if assuming they are shared by all.
To improve future decisions, the span of motives and perceptions is explicitly explored, and includes:
Aside from the real Voyager spacecraft, all the ideas so far are either inspirational fiction or estimates of technological possibilities.