For those curious about the state and roadmap for graphics drivers on FreeBSD, stop by this updated Graphics Wiki page. Roadmap items include updating to X.Org Server 1.14/1.15, enabling the new X.Org stack by default, updating the DDX drivers, updating to Mesa 10.0, and working on the experimental Wayland port for FreeBSD. The Wiki page is quite detailed and includes what's blocking most of the items from happening, for those looking to help out.
Most AMD Radeon GPUs now work with the upcoming FreeBSD 10.0 release but newer AMD Radeon HD 7000 "Southern Islands" hardware is only partially supported.
The HD 8000 "Sea Islands" and R9 200 "Hawaii" GPUs are also completely unsupported right now since their driver ported from Linux dates back to the 3.8 kernel. The FreeBSD Intel KMS driver code also doesn't support the latest-generation "Haswell" graphics processors until their DRM kernel port from Linux is updated. The Intel DRM driver port dates back to the Linux 3.4 kernel code as does their core DRM.
The graphics hardware with the best FreeBSD support would surely be NVIDIA products with the GeForce/Quadro GPUs being the only graphics processors with official (but closed-source) FreeBSD drivers. The NVIDIA FreeBSD driver is on a similar quality to the Linux and Solaris NVIDIA drivers, which is close to the NVIDIA Windows driver due to the common driver code-base.
Sans any hardware troubles, FreeBSD 10.0 is shaping up to be an exciting release and will likely see its official release in early 2014.