Let the hive mind of Engadget get that for you.
"I've found myself using my PC for a lot of conversations lately, and I'm also considering recording a podcast to share with anyone who will listen. There are tons of USB headset / microphones out there, and I'm hoping someone has some solid recommendations based on experience. I'll consider both headsets and standalone mics, by the way, but I'd like to keep the bill under $100 if possible. Help!"
That's for the gotta-have-its. I'm pretty sure there'll be pre/pro's available for ten percent of that price which perform just as well.
Eh, for $1400 you can do quite well with Outlaw's upcoming 997 preamp / processor. I'm sure there are other options around $1200 that will be quite competitive.
Then again, you could get an Onkyo 806 or a decent Yahama or Denon receiver if you need amplification and it doesn't have to be terribly high end.