I have NetBSD and FreeBSD.
FreeBSD's installation is quite easy. The installer also asks if you want to install binary packages, so you can have a full DE, some browsers and other stuff at the first boot. :) NetBSD's installation was a bit harder, the text menu's where a bit less handy imo. Just remember that BSD's need a primary partition and that their boot loaders aren't as fancy as grub(I recommend keeping grub if you already have that).
FreeBSD is my main OS. Its hardware support is progressing, for me atleast all my hardware is supported(CD and DVD burner, wired and wireless network, nvidia gfx card). FreeBSD can handle load much better than any other OS I tried(that is if you encode a movie you can just continue with other stuff without really noticing it). FreeBSD can install binary packages and compile them with the 'ports' system. With ports you have access to very much "Free" and "non-Free" software.
NetBSD is also a nice and clean OS, but IMO if you're not going to use it on some weird kind of hardware it doesn't really have something 'special'. I don't think you can get 3d on NetBSD. NetBSD can also install binaries as in the same way as FreeBSD('pkg_add'). And uses 'pkgsrc' to compile and install software. I didn't really liked it in comparisation with the ports system because it has far less things to install and doesn't have a proper way to upgrade your system. On the other hand its cool that you can use it on many other unix/linux systems too :)
Both BSD's can run linux binaries just fine(ut2004 runs atleast as fast as with ubuntu). There is also wine support, but doesn't work as good as on linux.
As for differences with linux...BSD has a different license, has its own 'base system' and is more unix like. Therefore most console apps differ slightly from the GNU ones. The default shell for root is the c shell(csh) and for any other users its plain sh. You can easily change to bash though. Updating the base system can be a little bit harder, but the docs discuss this very well.
Always check the excellent documentation :) Especially FreeBSD has lots of docs for preperation, installation and things you can do after installation(burn a dvd for example).