As with anything, you use whats best suited. But you shop around. Unfortunatly there's always a number of people that seem clueless, when you ask them why somethings broke or dos'nt work, there simple answer is "did'nt know you had to do that", when i've talked to people with seized or rattely engines and asked them when they did an oil change, it ranges from never to three or four years. Liken an engine to a heart, keep its arteries clean and clear, checked regularly and it'll last a lifetime. Regardless of how cheap or expensive an oil is, proper regular oil changes are essential, even the good stuff turns to crap eventually.
