I use the Spyder 3 and it does help, but monitor calibration is only 1/3 of the equation. You need to have a work flow from camera->PC->printer.
If you're using an epson printer with epson paper, then be sure to get the profiles from epson's website for the paper you're using (or whatever brand)...assuming of course that you are printing from some sort of photo editor which handles color profiles.
And if you are using paper for which there is not already a profile, you may also want to calibrate your printer.
Here's a pretty good site a found a while back in which the author has some good articles explaining
color management