it kindof depends if u want a dual tuner or not
if u do a good one that has a pci and usb interface is the dvico fusionhdtv dvb-t dual digital
it needs to be plugged into a pci and usb port but it only need one antenna input
also it can recrd and watch 2 channels at once
only problem is it has an ugly remote
if u only want a single tner try the nebula digitv pci, it has good software and good stability