I was an Infoserve customer, and quite
happy with it--it had everything I needed: cheap (< $20), enough hours,
(120), and fairly easy to connect (in the year that I've had it, I've had
maybe 3 busy signals). It was also one of the only ISP's that I could
achieve the top connection rate (33600 for my 33.6 modem, and over 50k
for my 56k modem. The only complaint is that sometimes my modem would
disconnect for no reason. There are many reasons for this--they said
that it could have to do with the brand of modem, so I won't totally blame
them. It was reliable enough for me to stick with them though.