There’s no right answer to this question; it’s a matter of personal preference. All stains differ from paint in that they provide color yet, at the same time, allow the wood’s character to show. A “solid” product is the most opaque and allows texture, but little grain detail, to be seen. A “semi-transparent” product allows some grain to be seen; a “clear” will show the most grain. Keep in mind that the more transparent the product, the more its color will be affected by the underlying wood; so, variations in wood color will be more obvious with transparent products, as will any natural blemishes such as knots and tannin. Also, opaque products usually last longer because they block out a greater proportion of damaging, ultraviolet rays.
To make your selection it’s best to try some stain samples on the kind of wood you’ll be coating.