I’m partial to Grasshopper. At my last company we had a blog post comparing Grasshopper to Google voice. Grasshopper picked it up and posted a link on their site. It’s still there today. We received a ton of traffic, and SEO value from that wonderful link.
When it came time to get a phone number for WP Harbor, the first place I looked was Grasshopper. I was sad to see how high their prices had gotten. Isolated, the pricing is fine. But I’m paying for a ton of >$50/month services, and they really start to add up!