best oil for my 2007 prius

LOTS of other threads about oil. I use 5-30 Mobil 1. Change the filter every 5k and top it off. Every 15k change oil and filter. 5 quart jug lasts a long time. Some mention toyota now says 10k complete oil change with synthetic (read the forums). Also change only every 6 months.
Buy it at walmart (or on sale) and take it to an oil change place. Usual charge is $10 with my own oil. OR get the drain plug addition talked about (makes it easy) and do it yourself if you are so inclined.

 

0w30 Mobil One for me.

 

Go to BITOG and a life could be spent discussing/analyzing oil. I use Mobil 0w-30, because got into it on sale. Engine runs nice on it. I change at 5k with Toyota Japan filter. Full flow filters are not that good, thinking they clean the oil well extending oil life is wrong. Pennzoil Platinum is widely praised for low wear numbers and other qualities. A lot of people see high iron wear numbers in Mobil 1 5w-30, but I haven't been convinced anything is wrong.

 

I use either Pennzoil Ultra 5w30 or Mobil 1 EP 5w30 or Mobil 1 0w30. I also use a Pure-One PL20195 filter. It's like double oversize, but it fits, and does a really good job at filtering. It makes the oil sump an even 4 quarts. I've had used oil analysis (Blackstone Labs) showing that EP is good for 10K miles; I'd bet the other two are too.