I've been working with my ISP to resolve the constant disconnects I've been getting, and I had a particularly frustrating call with a tech support person who decided she had a silver bullet to a months-long problem -- upselling me a 40 Mbps internet package. Because that's what she needed for her Netflix, so surely I needed this much.
Right now I'm 10 Mbps up/1 Mbps down, and when ESO isn't disconnecting on me, it plays just fine.
What's your Mbps up/down? Who's got the lowest that's still playable?