I've managed 12 MB/s down on Steam before on some seriously good cable. I've since been bumped down and am now at 3-5 MB/s.
Amazing thing is I can still browse the web, youtube, and use other devices in the house and it seems unaffected. DSL would cripple all other sources apart from the main download.
Still, I remember the good old days when 4 KB/s was quite decent. I still get pretty worked up when I see 3+ MB/s download speeds. My mind is blown each time.