Gutters keep rain water from your roof...
You definitely should have gutters any place where water will be pouring down from the roof on top of people, obviously.
The end of a gabled roof does not slope down, so it does not require gutters at the end of each section of the roof.
A hip roof ends with a slope, which you may or may not wish to gutter.
Judy's house has gables on the front and hips on the sides. We had only specified gutters over the front porch and back deck, but the builder (Jim Buss) had the gutters in the back run the entire width of the house and in front; he also brought the gutter up the side of the garage (facing the front yard) to protect vegetation.
The ground on the left and right sides of Judy's house slope away from the house, so drainage of rain from the roof should not be a problem despite those areas not having gutters, and she will not have the headaches of keeping unnecessary gutters clean.
To see different types of solutions, Google for gutter guards. There are basically two types of guards: a screen or mesh, and a "helmet". The latter is pretty expensive.
We have had a screen like the one below for over 8.5 years with no problems:
In 2008 when we last looked, Home Depot was selling this cheap plastic mesh by Amerimax:
despite the fact that customers gave it a terrible rating, reporting that the small holes clogged and the whole thing just fell apart in short order.
An alternative to gutters is something which breaks up the water flowing off the roof into drops. Google for more information or visit www.rainhandler.com
Manufacturers of such replacements claim that snow and leaves will not
accumulate on them. Even if they do, such things should be easier to
clear off. Accessories are available to divert the water away from entry
ways. The only major drawback I can see is that there is no way to move
the water away from the foundation as you can with gutters.