Your question is confusing. Spacecraft fly in space, so the ideal shape is spherical or cylindrical. Ascent lasts under 9 minutes, so shape is essentially irrelevant. Shape for original shuttle was predicated on re-entry.
Launch vehicles are not the same as spacecraft. The best launch vehicle profile is the one you always see, minimal frontal area with maximum volume - cylindrical with a pointy end. Not exactly irrelevant since the launch vehicle is often the single largest expense in the project.
I'd say the ideal shape for a spacecraft - in space - is the most functional one.
On a completely seperate topic, dimpling versus smoothness for aerodynamics has been discussed here and elsewhere repeatedly, a simple search followed by some reading should answer your question.
Unmanned space vehicles do not need provide a pressure vessel, so any shape that encloses the craft's functionality will do. However, for manned vehicles that are pressurized, round shapes maximize stress distribution.
At E X T R E M E L Y high speeds, even 1 H2 Molecule per KM has to be considered, but other than that, you're relatively free to make whatever erector-set tinker-toy you need.
This question has been satisfactorily answered. Spherical is the best shape for a spacecraft. Wind tunnel experiments have proven this. Though there is no air or physical wind in space having a vehicle that can accomplish a variety of missions is key in designing a 'well rounded' spacecraft. (haha)
As pointed out divots are not on golf balls. I am not a golfer and have no desire to be, sorry for the confusion. Additionally the statement about dimples making a ball more aerodynamic was not a question.
Mfgenggear,
There is no conclusive evidence of disk shaped UFOs. However, at great speeds a disk shape would create a loud sonic boom in Earths atmosphere. Rendering a UFO of this shape easily identifiable by this sound and shape, if it were observed (making it a non-UFO or identified object).