personally i've tried most if not all of the main distros. SUSE is very cool and i know a few people that swear by it. I like Mandrake, although i tend to prefer Slackware. Been with my Slack baby for a while now and its never failed me
support for distros...ummm an interesting question, I personally tend to use Google and places like Linuxquestions.org to find solutions. Generally I've always perceived that linux gives the source and tools to fix it yourself. However it really depends on how much you want to learn or know. you could use a GUI orientated distro (not that distros are all that different from one another) and not touch a terminal. Which is fine if you dont really want to learn much... or as i would say, have more of a life outside the matrix
It seems that your main concerns are for hardware support. This is essentially the kernel driver support base. The kernel contains all interfaces to supported hardware. So if you want the latest hardware support, like for your AGP for example, the change logs per a revision of the kernel at
will tell you what's what with any particluar module.
I did have a similar problem to your self, almost 2 years ago. My motherboard (Abit AT7-max2) automatically changes the agp speed, thus its stuck at x8. The older 2.4.x kernels didnt support it, however the 2.5.x (now 2.6.x) development kernel did. Slackware using the vanilla kernel enabled me to compile and install the lastest editions and thus get my radeon working for 3D. The thing is that a distro like Mandrake or Redhat have highly patched versions of the vanilla kernel, and so you normally either end up patching it back up or breaking parts of your distro.
My conclusion is that...
SUSE is good but you gotta pay for support.
Mandrake is good,but the real useful stuff is in the Mandrake Club...which you also have to pay for.
Redhat... essentially being the same.
Fedora... is free, and thus should have a good support base (haven't tinkered with it too much).
For me it leaves...
Gentoo... because you compile things (like the whole distro) you generally have alot of people that have had the same problems not to mention the fact that you built it from scratch (almost) anyhow and can take some days to finish. Also that fact you build it tends to mean that you know where thing is. I've also seen that they have a packaged radeon driver available and more tweaked kernels than you can shake a stick at.
Debian...is free and almost every problem i've ever had has been covered by a 'debhead' somewhere on some webpage.Although you can have issues with using the stable version rather than the unstable(unstable being what you probably want). But you are going to have to install a later kernel, but apt and the package manager, should sort you out nicely.
And my fave Slackware... you can compile it yourself like gentoo, however the fact i can go from zero to installed/configured in 45 mins with little fuss is just sweet. And as mentioned earlier the vanilla kernel and simplicity, do it for me. Some say you can learn other distros like redhat, but if you learn Slackware, you learn Linux
Support everything is covered (it is one of the oldest distros), ocassionally somethings are harder to find out than others, but its fine. Just out of distro propaganda you can install the new slackware 10, it comes with a 2.6.7 kernel as a option, saving some hassle.
hope that helps