Yoroshiku onegaishimasu is a commonly used phrase when meeting someone for the first time. Is there a more suitable phrase that would more accurately convey nice to meet you? Could I say oaide kite ureshii desu?
It depends on what you mean by "nice to meet you"
a) as the phrase, where it carries no / very little meaning of actually being happy to have met the person (instead of never ending up meeting)
If a), "はじめまして" is probably the most natural one.
b) To express actual delight of getting to meet the person, e.g when you have been really looking forward for it.
If b), I can't come up with anything very good, but maybe "あえてうれしい" or "やっとあえてよかった" (The latter one is stressing more the fact that you have been waiting, i.e. would be like "I am glad I finally got to meet you"