AC_A340 brought up the question of ADSL vs. Cable Modem, so here's what I know on the matter.
Personally I use a cable modem, because when I was shopping it seemed a little cheaper. But my roomate wanted Cable TV as well, but if you don't want that then ADSL probably would be cheaper. ADSL is available in my area as well, and I have friends who have it.
With ADSL you have specific downstream and upstream transfer rates. You are guaranteed these, and often you are offered a choice of what speeds you want (faster == more expensive). Generally downstream is faster because that is what most people use most of the time (you only use upstream when sending things, so you don't really need fast upstream unless you are running a server). You can SDSL which has the same speeds both directions, but since most people don't need it it's generally not worth paying extra for.
Cable modems do not have a set speed, but their top speed can exceed ADSL. But you are sharing your connection with your neighbors, so the more people using it around you the slower it goes. And since cable TV networks were designed for downstream data (TV), they can be slower for upstream, but again this doesn't affect most people that much.
But sharing isn't really that bad, because past the connection from you to the provider, it is shared no matter what type of connection you have (DSL, cable, ISDN, or dialup). And here in San Diego anyway, RoadRunner guarantees that the network will always have better than ISDN performance, so if it ever gets that slow they'll spit things up so that it's faster again.
ISDN is older, more expensive, and slower than DSL or cable, so unless you're in an area where that's the only high-speed option (short of a very expensive T1), there's no reason to get it.