Yep. One big partition. It's just not worth fighting with Windows over where stuff goes.

Just for another viewpoint, I think there is a lot of merit to having at least 3 partitions. One should be your C: Windows partition, big enough to hold Windows, along with anything that you're FORCED into putting under C:\PROGRA~1 (because of lazy install programs and the like.) Another should be your programs partition, where you can hopefully install all your apps, save for shared DLL's. The rest of your partitions should be for your documents, movies, and whatever else.

Why separate partitions? Well first off, having the Windows partition separate enables you to reformat your Windows drive when necessary, reinstall the OS, and then just re-run the installer for those apps that have enough registry and DLL dependencies as to not work after a reinstall. For me, between a third and a half of my programs can survive an OS recycle without needing to be reinstalled, and for those that can't, at least you've got your existing files on another drive that didn't get wiped away when you reinstalled Windows (yes, I know you can choose to keep everything outside of C:\WINNT and C:DOCUME~1, but it's always good to format your Windows partition when possible.)

The other thing is if you're writing a lot of apps and documents to your Windows drive, it's going to get fragmented, whereas if you're writing to other drives, your Windows drive stays (in theory) nice and clean. Finally, keeping docs seperate from both your Windows crap and your applications is a good idea, since if you want to recycle your entire system, you don't need to dig through application install directories for your files, you just format your Windows and application drives and go. Microsoft does try to assume you live in C:\DOCUME~1, but that can be changed via a registry setting.

Another thing I do is keep a separate drive for my really large files (movies and the like) with a high allocation unit size for better performance. That, along with not having other types of files interspersed (assuming you're defragmenting on a regular basis) really helps. If two or more of your partitions are on the same physical drive, there's some science behind which should go where (for best performance), but I forgot how that works, and am not entirely sold that it makes a tangible difference.

Oh, and if you don't like the idea of having to browse to different drives for everything, you can hang any drive off of a "mount point" in the Disk Administrator management console.