I know people hate answering these questions. A distrobution is really a personal choice..
If you want something that works (out of the box) choose something like Mandriva, or SuSE, or Fedora (although it's fishy on its media support)
If you want something (this is what I use) that is fast, stable, but you have to set up yourself (so it requires a bit of knowledge of your hardware), I would suggest Arch. It comes with E, and is faster than anything but a stage one gentoo system (at least in what I have seen). After you have it installed, you can download HWD (which is the same hardware detection tool that Knoppix uses), and use it to detect your hardware, you still have to set it up yourself, but once you do, you don't have to worry about it again... Arch has a good package management system that is uber-easy to make packages. It's like Debian's apt-get, but pacman (commands are slightly differnet, but it seems easier to use to me... although apt-get is stupid easy.. pacman is really stupid easy..)
Yes, I know I have become one of the mindless ArchLinux Zealots....but it works for me, you might wanna give it a chance...
Or maybe Damn Small Linux... it's itty bitty.
Your problems with the mbr are prbably do to your multiple drive config, have you looked into using Grub? It's the next wave in bootloaders (ewll.. i like it, again it allows slightly more, but lacks Lilo's simplicity)