What do you want to watch?
Local over-the-air broadcasts?
Unencrypted Digital Cable (Clear QAM)?
Digital cable in its entirety?
Nowadays, analog tuners aren't worth much since broadcast television and cable are digital now, but it's useful if you have a VCR.
A hybrid or Digital tuner is what you want, Dual tuners will let you tune into 2 channels at once, so you can watch or record 2 programs at the same time. Watch one show while recording another. if you love TV it's totally worth it. One thing to keep in mind is that you can only tune into an unscrambled signals, you can view local channels and basic cable (in my area that only covers 80 channels) unless you hook up a cable box. In my experience, the HD channels are generally scrambled. Some also have radio recievers if you want to listen to music.
A few companies have started making CableCARD tuners for PCs that will let you tune into the scrambled digital cable channels without needing a cable box if you rent a CableCARD from your cable provider and is generally a lot cheaper than their boxes ($2 for me) The selection is limited at the moment. You can pick up a ATI digital cable wonder off ebay (it supports 1 stream and is now a depreciated product, but it works and can be had for 80-100 bucks) and theres the Ceton InfiniTV 4 for $400 if you join the beta prograam (or eventually with stock firmware) you can expose the tuner to the network and view it on any PC on the network. Get that if you REALLY love TV. If you are looking to the future, Silicon Dust is partnering with Hauppage to bring both a USB 3 stream tuner box and a networked version of the same, and Ceton is going to be releasing a cheaper 2 stream card and an external 4 stream box.
Remember a few things: While HD cable is on the rise, the majority of channels are still standard definition (480p), so don't be surprised if you get recordings that aren't in HD.
The tuner Stillhouse linked is a good one 2 tuners and an FM radio. If you want to watch TV from afar you might also consider getting a remote (and reciever, the card has a port for an IR reciever)
edit: Hey stop posting while I'm posting
Originally Posted by Emerican
i have one more question, ive been reading in reviews about channels converting to something else, only question i have is will i be able to record/ watch the channels i get on my cable box? (i think it was referred to a step-up box aka cable box)
What do you mean channels converting to something else? You will be able to record channels from your cable box if it is connected to you tuner card, just remember that you have to set the box to the right channel yourself.Edited by BirdofPrey - 5/2/11 at 7:57pm