I agree with Jim: mic technique is more important than the mic.

Try singing a phrase from one of your own multitrack recordings. Sing the first one as you normally would, and mix that section down.

Try another take singing another foot away from the mic, mix it down.

Try another take with the mic placed somewhere else in the room...sing into it slightly from the side, and mix it down.

Chances are, these three takes are all going to have a different vocal sound...same mic, different technique and placement.

Capture the best possible sound you can at the source, before you press that record button, and you might not feel the need to go out and buy yet another flavor of microphone.

http://www.soundclick.com/MarkKaufman