Relply ASAP!!!La Botte or Via Veneto or Locanda Portofino (??or Wilshire)
which of these would be best for a romantic birthday (50th!!) birthday dinner...equal importance of food and romantic ambiance...
La Botte is great, but I don't know if I would consider it particularly romantic. Haven't been to either of the other two.
Have you considered Valentino? I think that would be exactly the type of place for which you are looking. If you go, make SURE you request Paul as your Captain/Waiter -- he is AWESOME!
For food, I'd recommend either LaBotte and Via Veneto over Wilshire and Locanda Portofino. Between La Botte and Via Veneto, it depends on what sort of atmosphere you're after. I love both. Via Veneto is livelier and louder than LaBotte. Also, at VV the tables are really close together and the service can be either charming or disinterested and rushed.
Wilshire is the most romantic of the list, by far. Via Veneto is one of my favorite restaurants in LA, but it's loud and tables are extremely close to each other, not what I consider romantic. Portofino is great, but with a view of the parking lot and being in a strip mall, has more of a locals vibe and isn't romantic, either.