I use a Shure Beta 57A because of it's broad dynamic range and great vocal presence. I use it for vocals and to record my bass guitar as well (mic my amp).
What interface are you using to connect it to your computer?
Well, there are a few ways to connect. Some laptops and most towers have mic inputs, but they aren't the highest quality available--they are passable. There are several ways to go to improve your input:
1. Griffin iMic: http://www.griffintechnology.com/products/imic/
If you buy the mic I suggest you'll need an XLR to 1/4" plug adaptor and a 1/4" to 1/8" plug adaptor as well. Then you can plug directly into the iMic.
or if you want to go all the way (music production capability)
The Samson C01U mic looks like something that would work quite nicely! I might even consider Samson's C03U, http://www.macobserver.com/review/2006/12/21.1.shtml
their next step up from the C01U, and at $129 from some sellers, it's well within my price range.
The Protools MBox looks worth considering if I decide to get into more sophisticated recording.
The iMic adaptor is good to know about if I should look to mics without USB capability, but the Samson mics look like the one's to go with.
Thanks so much for your very helpful input.....I really appreciate it!