Pinnacle is best. But cost is more than double than other branded product,

You can go for forntech USB tv tuner/ Frontech external tv tuner.
Their price is best. Check rediff shopping:
http://shopping.rediff.com/product/frontech-external-t v-tuner-card/10414619
http://shopping.rediff.com/product/frontec h-external-tv-tuner-card--box-for-lcdtft-monitor-1-yr-wty/1037751 3
http://shopping.rediff.com/product/frontech-usb-laptop-desktop -external-tv-tuner-card-box-lowest-price/10428719