For instance I own a Wii guitar for Rock Band that I use to play Frets On Fire during my off time. Works out of the box, all I had to do is setup the button configuration from within the game itself.
I also have two external hard drives using various Linux file systems on multiple partitions. Each partition mounts immediately once the external hard drive is plugged in. And saving the best for last, I tested things out by purchasing a random external DVD Burner (Sony brand) that I picked up at random from Best Buy simply because it was cheap.
Then I took it home, plugged it in and sure enough it works perfectly.
It's not Linux that is the problem
Now it seems to me that hardware compatibility is not really something that Linux struggles with. And in those rare instances where it is a problem, one can almost always look to the vendor for a place to blame.
In other circumstances where the vendor is not the culprit, the issue may be with the end user failing to understand how the specific hardware is supposed to work with the chosen Linux distribution in the first place. For example, setting up dual-monitors with NVIDIA or ATI cards.
In Windows, this is pretty easy. You can do this from display properties. However in Linux, there are a few things to be aware of. First, you will need the proprietary drivers for either of these. Second, you will want to use the provided control utilities for either versus the less reliable desktop manager equivalent.
As you can see from the above linked images, setting up a dual-monitor desktop is actually pretty easy with Linux. It is just a matter of understanding which tools to use and which drivers to put to work for you. And for so many individuals out there, that's the rub. Learning a new operating system or discovering the quickest approach to making sure your existing hardware is compatible sometimes just means diving right into the middle of things.
Suffice it to say, there is no single hardware compatibility list that is going to be totally up to date or have every single piece of hardware out there listed. It's a nice thought, but highly unlikely to happen in my life time.
Alternatives, then? I would start off buying laptops pre-installed with your preferred distribution (Google is your friend here) and do some testing before totally assuming that you have all the answers with regard to compatibility with existing desktop hardware. Ive been doing this for years and thus far, this simply combination of research and common sense has yet to fail me.