In my experience tho, Likewise fails to install any of its dependencies - you gotta really watch out for that. In particular make sure that NTP is installed (many distros don't include it by default) as you usually won't be able to join the domain unless your PC is in synch with the server.
Using Likewise Open (and a little fiddling around) I have managed to get Linux Mint 5 (based on ubuntu) and Ubuntu 8.10 to join.
Opensuse 10.2 will join the domain right out of the box as long as you don't try to join during install (even though you should be able to). You even get a proper domain login prompt at login screen - none of the others i have seen do this. Just configure it after, making sure you config it to look at your server for NTP too. Later versions of Opensuse (i tried 10.3, 11 and 11.1) are all broken in this respect, and domain joins to AD just DO NOT seem to work. Someone break some fingers! lol