Sometime last year I fled Earthlink DSL as the connectivity became unreliable and the customer service deteriorated. The only other option for my house was AT&T. Unfortunately, it really hasn't fared any better. In the middle of January I starting running a daemon that would check the connection via a ping every 5 seconds and record the results. Now I know exactly when the connection goes out and for how long. Here is a record of all the extended outages since the beginning of the year. This doesn't count the numerous outages that lasted less than 10 minutes. Time is given as hours and minutes.
2/03 0:20 (phone service too)
The only reason I have resisted moving away from AT&T is because my only other alternative is Comcast. I had similar experiences with that service many years ago and have been reluctant to move back. The only other DSL providers that serves my address is Earthlink. I left Earthlink a year ago because they were also unable to keep my connection working reliably. At least with AT&T the people I talk to on the phone speak english and seem to care, even if they're too incompetent to actually fix anything.
Here are some uptime percentages for the mathematically curious. If I don't include this past weekend, my monitoring covers 79 days during which my service was out for 954 minutes. That's 99.16% uptime. If I include the outage from this past weekend I get 3114 minutes unavailable over 81 days. The uptime plummets to 97.33% which is pathetic.