Also I still have a couple of boxes running W-98 for convenience and family use; I find that this is relatively straightforward and inexpensive enough rather than dealing with the hassles of a multiple-boot system.
Although Debian isn't as flashy or end-user-y as some of the other distributions, they have a better security record, and apt-get rocks!
Keeping your system up-to-date is as easy as:
apt-get update apt-get upgrade
I administer several servers, and they all run Debian.