Oh man, we didn't have time to reply. I have had Earthlink DSL (damn wish I could get their cable) for 4 years.
They are a decent ISP:
Stable. Used to connect for 6 months straight with no problem. Little shaky lately; I blame Sprint.
Solid webmail but crappy anti-spam (Bright Mail, go figure).
10 meg web storage for each of 8 custom e-mail addresses.
4gig per 30 days (capped after) Usenet access with 4 days retention.
Same dirt poor tech support as everyone else (except my local cable company, which was pretty darn good).
Geez, what else... I know I kept them for a reason...

Those cable prices seem quite insane. My local cable company offers 6mbps cheap using eveer-changing monthly offers: $20/month for 6 months, first 3 months free, etc. With no contract, you can cancel and resubscribe whenever. I took thee 3 months free, but decided 6mbps was simply TOO fast, and their lack of extra features didn't make up for it. So, back to Earthlink 1.5mbps DSL running on (goddamn) Sprint.

For bandwidth tests, I use HTTP downloads from Microsoft (couldn't saturate 6mbps), Amazon (happily saturated 6mbps), and PaulWay's server (always surprises me, if it still does HTTP). Then try a torrent for fun and watch your bandwidth max out. My conclusion was that 6mbps+ cable was only good for multiple-stream transmissions like torrent. Single HTTP or FTP connections just couldn't fill the pipe. Thus, not worth it for me.