Napa Synthetic 5w30. On sale for $3.79/qt this month. It's rebranded Synpower.
Another good deal is PP 5w30. $22.66 at Walmart for 5qt, and there's a $10 rebate.
PP is cheaper after rebate, but it's the big 5-qt jug and you have to wait 3-4 weeks to get the rebate, and some people don't like WM.
The advantage to Napa syn is the single quart bottles, so when you just have a little bit left, it's just one quart left or half a quart in the same small bottle, rather than having a big jug left behind for just a quart or less. Plus, the single quart bottles are easier to pour from.
Either one will serve you well.
The M1 AFE 0w30 is also a good choice.