If you ever have a chance to visit Jerusalem, a visit to the Holocaust Museum is a bit out of the way but is a definite must! The museum is amazingly well done and very historically informative (about WWII in general, not just about the Holocaust).
We spent a couple of dollars to get the audio guide and expected to be here for about an hour or so... 4.5 hours later, we realized the time had to hurry through the rest since we didn't expect to be there so late (and hadn't eaten all day)!
You can't take pictures inside the museum, so you'll just have to take our word for it and go check it out for yourselves. Admission is free so you've got nothing to lose!!