When it comes to fittings, the best garden hoses have brass fittings. However, you will find many cheap hoses come with plastic fittings. You should AVOID plastic fittings at all costs as the plastic couplings are prone to cracking, breaking, and leaking. In many cases, you simply cannot tighten these fittings properly for fear of breaking them, this results in constant leaking. Plastic fittings are also susceptible to damage by the sun's UV radiation.
Chrome plated metal fittings are slightly better than plastic as they stronger, but many will rust and fail if left out in the yard all year long. Brass fittings are thicker and typically have an octagon shape. These are the most durable and you can use a wrench to tighten them and prevent leakage.
No matter what type of fittings your hose comes with, the best way to prevent leakage is to be sure you use the rubber washer at both ends. You should also look for hoses that have a sleeve at the spigot or "female" end to help reduce the chances of the hose kinking. The sleeve can be made of nylon mesh, a metal coil, or thick rubber, these hoses may cost more, but you will find they are worth the money.