Chau.....I would suggest you to start with Beethoven and Mozart. Their music are somewhat more musical and easier on beginner's ears. Comtemporary music are great, but I am sure you don't want to bore yourself for 20 minutes and not knowing which direction the music is taking you to. Here is some work I think will be great for you to listen to....actually, these are the must have!!
BEETHOVEN:
Violin Concerto
Piano Concerto no.1 and 5
All of his symphonies!!!!!!
Piano sonatas (moonlight is especially easy on beginner's ears)
MOZART:
Symphony No.40 and 41
Divertimento k525
Turkish March
Violin Concerto no.3 and 5
OTHERS:
The four seasons---Vivaldi
As you get more used to classical music...you will find out some other great stuff too. But for someone who still listen to Canon...my list should be more than enough.