What's the best neighborhood to live in Los Angeles if you are 25 and money is no object?

Haha just saw the smaller part of your answer, sorry about that. Given the choices you are looking at, I would say Hollywood Hills and West Hollywood. Totally depends on what you tend to like to do... but those would be the most fun and nicest for your age, I would imagine. Beverly hills is of course really posh and lots of shopping but older vibe. Hollywood is super gross in places, unsafe and overall just not worth it. So many better bars or fun activities in other places.

Hollywood Hills is beautiful because the hills are beautiful and you can hike, etc. And you can drive elsewhere to hang ;P But not great for walking. However, if you are in the hills around Sunset blvd. west of Fairfax, it's a great combo of posh nightlife, very LA classic urban feel and fun wacky things, coffee, food. Not the most walkable and charming but still 100x better than Hollywood proper.

As for West Hollywood that's also the other best choice. I would say the #1 best of your options. It's a thriving gay community in most areas, so if that's good or bad for you, you may have to take that into account. Great neighborhood areas, little parks, tons of food and bars, etc. Seems like a fun place and there is always something going on. Plus, it's central and easy to get to many fun neighborhoods around it.

I think it depends completely on your personality. I would say Silverlake/Echo Park (if you're into the urban/hipster thing, great coffee, bars, food, eclectic, arty, etc). You can find lots of nice, interesting places if money is no object.

Also definitely Santa Monica or maybe even Venice. Venice might have slightly older vibe than you want, (mid 30's, young families) but it's still great and more eclectic and arty than Santa Monica. Main st. is a great option to get the best of both worlds - The arty, beach vibe, and the posh, fun Santa Monica feeling with bars, food, etc. Santa Monica around the 3rd st. promenade has great shopping/food, bars and of course the beach and potentially beautiful views where you live. A good mix of nightlife and day time stuff. But it's touristy, if you're not into that it wouldn't be a good choice.