SuSE's claim to uniqueness lies in its Yast administration tool. SuSE may also be a good choice for the ham considering Linux as traffic on the Linux-hams mailing list indicates a maintainer is active keeping the AX.25 utilities working with the latest SuSE releases. This is a sampling of some of the current popular distributions. It is likely that in the next few months today's star distributions could be yesterday's news. Within the last year Mandrake has gone from being ideas to today's hottest distributions.
Mandrake is unique that it started with and became extensions of well known current distributions.
To get an idea of the extent of current Linux distributions check out Linux Weekly News and follow the Distributions link. Top Getting Prepared for Your Linux Installation. As I alluded to above, grabbing a couple of texts on installing and running Linux will prove its worth once you decide to actually take the plunge. The very first thing you'll need to do is find some space to install your new Linux system. While you will still need some of that space to add more stuff to your Win side of the computer, most of that space can be dedicated to Linux.