[X4U] microphone for podcasting

[Kansas Territory]

can anyone recommend a microphone for podcasting..

I own several microphones.. I've used over the years to record  
guitars etc..
I run them through a "decent" mixing board etc..  and have all that  
routed into my audio in on my mac.

I've been recording a weekly podcast, using Garage Band  but I've  
been having a heck of a time getting what I think are decent levels  
and quality when I try using these microphones.

Sometimes I use my sons iMac,  when I'm recording outside, and we use  
the built in microphone on his iMac, which for me works well enough,  
given the situation and we are outside etc..

But I'm just looking for some suggestions on a good microphone for  
recording the "spoken word"   I've tried like a radio shack shure  
microphone ?  that runs through the mixing board.. and I've used some  
cheap USB mic,  but both of these seem weak in what they pick up,   
and if it you get to close, they become to sensitive.

KansasT