1. We don't let licenses get in the way of making good technical decisions. This means that, for example, we had no problem with importing DTrace and ZFS.
2. We have more of an emphasis on doing things right. This often means that it takes longer before we acquire new features; but it means that once we acquire new features, they work and aren't likely to be removed or completely rewritten any time soon.
3. We develop the kernel and userland in tandem. This allows new features in the kernel to be accessed from userland faster (usually immediately) whereas in Linux there will often be a significant lag time before your libc supports everything in your new kernel.
4. We have stable development branches, and we're serious about them. Not "stable" in the linux kernel sense of "we think this won't crash" -- stable in the sense of APIs and ABIs, so that code you compile on FreeBSD 8.0 will work without recompiling on FreeBSD 8.4 five years later.
5. Our stable branches apply to the kernel, too. You can compile a kernel module for FreeBSD 8.0 and use it on later versions of FreeBSD 8.x, too -- linux, in contrast, has on occasion broken kernel ABI compatibility in security patches. ("Gee, do I want to apply this security patch, or do I want to keep using the video card driver supplied by my vendor?")
6. Personally I greatly prefer the FreeBSD ports tree over the linux equivalents, but that's just a matter of taste and what you're used to.