I don't recommend to my clients they use us-east-1. It's the oldest and most prone to outages. I usually always recommend us-east-2 (Ohio) unless they require West Coast.
and if they need West Coast, it's us-west-2. I consider us-west-1 to be a failed region. They don't get some of the new instance types, you can't get three AZs for your VPCs, and they're more expensive than the other US regions.
