ok. lets try to clean up the clutter here. first off, EVERYONE please

first. most of what you have mentioned has already been posted elsewhere.
ok. now to explain some of this. first off, most of the currently available radio tuners designed for pc/mac use have really crap reception compared to a standard headunit. so if your headunit brings in your local station pretty well with some minor static here and there, expect to get constant static mixed with the music and mono audio. thats the best case scenario.
the Radio X-treme posted above: all i know is that David (developer of the frontend Centrafuse. check the frontend forum for more info) owns one and has had plans from the start to have it fully integrated in CF along side support for other tuners using the Radiator program. this of course doesn't answer for other frontends, just mentioning that there is another user here who may or may not have had good luck with it. i personally haven't been able to get any evidence as to its reception quality.
the D-Link usb radio has gotten some decent reviews from other users here. one good bit of news is that i have heard that hooking it up to your car's antenna is pretty painless sans some basic soldering and wiring and whatnot. it may or may not get good reception, but again: nowhere near as good as a standard headunit.
the radio shark really has nothing going for it. all I've heard is JUNK. crap reception. crap software which is proprietary. no radiator support (which most frontends rely on iirc). avoid it at all costs.
now that thats out of the way, i do want to point out that there is a homebrew tuner in the works right on this very forum which is being built specifically for the carpc community. with this in mind, its being built with parts that were designed for a car environment (mainly the tuner itself and other closely linked chips) so its going to have headunit quality reception. Also it has already been slated to have support for AM/FM/ and RDS (in-stream data such as song info, station call letters, weather, etc. broadcasted from the station to your radio which is then displayed on the headunit) functionality whereas past and current pc radio setups have just had FM capability and nothing else. needless to say, this IS the holy grail (that is unless Zip-Lock wants to get a few words in here on that

) for carpc radio. and before you post more questions about this, please read atleast the first page of
this thread before posting aimlessly into the night.
g'night all