each person is different. so it simply depends on if you are the type that can simply walk into a shop and pick something of the flash wall (which plenty of people do im just not one of them) or if you need to have a design that is totally you and no one else.
i will say that there is almost no way to be entirely original because there are so many tattoos out there almost everything has been done so dont get too upset if you see someone down the road that has one similar to yours.
as for picking one, the way i have always gone for myself is what tattoo will best tell the story of what is going on in my life at that time. that way, fifty years down the road even if it has faded over time i can still say that its there for a reason. some tattoos may look stupid to others but as long as it was a chapter in my life i couldnt care less what they think and suggest the same to you. hope i helped a little.