If you need ACM/VCM then the TBS 5925/6925 is an excellent choice.
If you dont, then any of the stv0900/stv0903 demod cards I'd recommend. The TBS 5980 and the Skystar 2 Express HD PCIe are both around $80 shipped and are excellent cards. The Skystar one is probably my favorite out of all 12 cards I own. Its fast and reliable.
Unfortunately all the cards Ive mentioned wont run on the mainline Linux kernel. I have open source support for all of these in my v4l-updatelee kernel though. Ive also added additional functionality like spectrum scan and IQ plot.
UDL