So I'm pretty well versed in classical music, but I think I've hit a wall here.

To explain, my favorite composer is Rachmaninov. I absolutely love his style of music (Romantic Era). Now, I've also found a few other compsers that I really really like, such as Grieg, Samuel Barber, Tchaikovsky, Liszt, and Saint-Saens. Of course, I also have the catalog of the well known stuff...

Anyways, I'm a big fan of Adagio music, and wanted to know if anyone had some reccommendations for me. Is there anyone else like Rachmaninov at all?

Also, anyone have any disc reccommendations for some traditional Japanese or Chinese music arrangements?

Some possibilities: Elgar, Debussy, Fauré, Delibes, Borodin, Rimsky-Korsakov. Neither is exactly like Rachmaninov, but then Rachmaninov was closest to Tchaikovsky, whom you already have. Basically, look for late 19th/early 20th century stuff. Also try Chopin if you haven't already.

I'll second for Chopin, though you probably already know that.