I mostly use Costco 87 octane. It is Top Tier certified and almost always the least expensive brand in my area. A real plus for me is that I don't have to travel far to get to a Costco pump. I sometimes use Sunoco 87 octane, which is also a Top Tier gasoline.
I found this post to be helpful. I am old and went for too many years following the 3,000 miles rule. I know things have changed, so I am reluctantly willing to streach to 5,000 miles, but 10K is way out of my comfort zone.