I've heard all these stories about 100 times, and they just get better every single time I hear them. There are some really creepy places in Hollywood, I used to live a block from the Ambassador Hotel (for those who don't know, that's where Robert Kennedy was assassinated, Oscars were held, Emmys too, but way back in the golden age of movies)...
The building is ominous and huge even though it's falling to pieces.. We got to get very up close and personal to the building (it's heavily used for filming and therefore heavily guarded so no entry allowed) for a local festival they were holding in the parking lot. We explored it's perimeter and what a grand place it used to be. I just wished I could get in and really see what's going on in there.
The only haunted thing I have heard of is when some film crew was there, a couple people on the crew saw people in the windows or leaning out of windows (some windows on upper floors are broken or open).
The building I lived in what was also an old hotel restored and converted into apartments. Nothing confirmed on my end, but lots of odd footsteps and the occasional fridge closing (I lived alone in an apartment with bars on the windows, no one could have done it).
The area I lived is very historically ignored (as is with a lot of Los Angeles areas), but used to be a hotbed of celebrity's. The Picadilly (named for Mary Pickford) is around the corner, the Gaylord, the Ambassador, the Langham, the original Brown Derby restaurant (now torn down and replaced by a strip mall cleverly named after the historic restaurant).
I'm really sad that Hollywood/Los Angeles doesn't try to preserve whats left of it's history, they'd just rather tear it down and build something new. And with so much history, it's very hard to find anything about ghosts out here, unless of course they're famous.
Sorry I'm going on a political rant that you guys probably don't care about... never mind!