Cable internet in Holland, especially chello(1536kb/128kb) and @Home (2mbit downspeed), is much much faster than it's adsl counterpart. Fast adsl (up to 8 mbit/s down) is possible, but very expensive (about 100 euros a month for 8mbit/s down).
chello and @Home offer a faster product for a lower price.
In the past there were problems with reliability of cable internet, but nowadays reliability is good. But adsl may still be a a bit more reliable than cable.
Cable company's like upc/chello and wanadoo/casema did and still do not have a good reputation for their service, but still I'd recommend getting cable internet from them (especially upc/chello; when you have casema/wanadoo in you town, you may consider adsl, because their speeds are lower)
For adsl see: www.kpnadsl.nl and www.bbned.nl
For cable see: www.kabelbedrijf.nl (check what company offers cable internet where you live)