eenie, menie, minie moe....... that led me to Dumbledore, it was teh only way I could pick, even if it was just a freindly competition.
(which BTW is the only way I think these two would have ever faced off, also one must note that LOTR is said to take place in a more ancient time and HP is supposed to be modern times, so they would never really be able to "face-off")