Gutter guards work for me because the trees in my yard have large leaves that don't get caught in them. There are several types of gutter screen products. They all work sort-of well. I have the plactic snap-in gutter screen made by Swears of NC.
If using a gutter screen product, just make sure it is installed right side up so that the ridge can catch the rain.
Steve is correct if the area, soil, and Grade (slope of the ground) where you live permits not using a gutter. If so, then go ahead.