From ** pulykamell **
Baroque? … Besides Bach, of course there’s Telemann, Scarlatti, and Pachabel (of Canon fame), but I don’t know much outside those guys.
For Baroque, there’s also Vivaldi, and Albinoni.  There’s an Adagio by Albinoni that is an incredible piece – one of my favorites.
And if you have any interest in anything pre-Baroque, there is plenty of good Renaissance music.  Although many things before the Baroque period are by that famous composer, “Anonymous”,  Purcell is a name that comes to mind.
 Purcell is a name that comes to mind.
I have a fun CD of Renaissance/Baroque era music called “The Art of the Bawdy Song” – in addition to having some very good music, the lyrics are pretty fun, too.
As for other composers…
Samuel Barber – probably best known for his “Adagio for Strings” (which was used heavily in the movie “Platoon”).  He also has some good piano pieces, with a jazz/blues feel.
Sergei Rakhmaninov – a 20th century Russian composer.  Has some great stuff.  One of my favorites is his 2nd Piano Concerto.
Rimsky-Korsakov – has a great symphonic suite, “Scheherazade”.
If you like symphonic music, I would also highly recommend the soundtrack for “Last of the Mohicans” (the movie from the 90’s, with Daniel Day Lewis).  The first 9 tracks on the soundtrack are all by the same composer – and work around several common musical themes – and it’s some incredible music.
As for cultural music, if you like Celtic, check out Deanta.  Especially the song “Culloden’s Harvest”.  Haunting…
And Nocturne says:
And of course, I will always recommend Chopin (look at my handle). Nocturne in C sharp minor is my favorite.
Yep, I’ve got to agree there – I’d always recommend Chopin.  The C sharp nocturne is one of the best.  I’m also very partial to the Nocturne in C minor (probably since it was one of my senior piano recital pieces in college).  And with Chopin, don’t forget the “Fantasie Impromptu”.