Yes, you're right. Rachmaninoff is amazing at expressing a deep sense of nostalgia and regret.Take this seldom performed prelude in F major:I just love that moment at 2:19
As others have suggested, there are simply too many to list.But if I tried to be objective (however possible that is when considering melody), I can think of nothing finer that the second movement of Ravel's piano concerto in G Major. Whatever beauty is, it's that.
I think I'll stop now before I accidentally link to every Chopin piece in existence...
0:52