The AT2020 is going to sound detailed, and more than good enough for a podcast. It is definitely one of the better mics for this type of thing...I really don't want to get into what most people are using
As for myself, I just use a 58 for our podcast (my office where I record the show is a bit open). Something like this would work well: http://www.amazon.com/Technica-AT200...sb+dynamic+mic
I just go dynamic because I don't want the sound of the room all over our show. Our host is using a cheaper MXL condenser and it sounds fantastic. I mean, really, most podcasts end up at 64kbps mono, so it's pretty hard to choose something that would be disappointing.
There's a link to our show in my signature if you want to hear the mics in action. You can tell that Gabe (our host) has a bit more definition to his voice (using the condenser). I'm the Tim with the 58, and the other tim has a headset (you'll know which is which). Full spectrum show I guess