At the risk of sounding a bit like a broken record, have you given Knoppix a thought or try? Just as Mandrake is basically Red Hat with KDE as the default environment, so Knoppix is Debian with KDE, an easier install, and more leading-edge software (It's based on the testing/unstable branches -- but don't let that put you off). You can experiment to your heart's content in a CD-bootable full Linux evironment "sandbox" with a configuration file saved to an arbitrary hard drive, then install it if you like it. While the install is a little rough around the edges, because of auto-configuation it only takes about 20 minutes (the script is on the CD) and it's easy to smooth out those edges -- and polish the whole thing to a bright gleam -- with the information and interactive help available at Knoppix.net (see below); there's a whole forum devoted to HDD install, for example.
What it amounted to, for me, was the editing of a couple of script files (fstab and bootmisc.sh), copying some desktop icons, and downloading some non-free files -- nearly all of which was extensively documented. Being mostly out of work, the free part was very attractive, as well; if not for the fact that I teach Windows to seniors, I probably wouldn't bother to dual-boot much any more (I'm running about 80% Linux now, and I'm still learning). To say that I'm pleased with the install is putting it mildly. I'm much happier than I was with my SuSE Professional install of a year ago, though part of that is that Linux has really come a long way in that time, as well.
It comes with a full development environment, OpenOffice.org, The GIMP, Mozilla, and all the other stuff you would expect to see in a basic-plus install, even in its CD-bootable mode.