Well I don't have an actual favorite chord but my favorite arpeggio is of A Major 7.
This is kinda' stupid topic but hey, i'm bored.

Well if I knew how differentiate between them but unfortunately I am tone deaf due to a lack of musical training. If I did have such training not sure how far I would succeed in this but I love music so I am quite envious of your knowledge of the musical scale.

I like the piano keys, not the black notes, but the other regular ones in the beginning of Vanessa Carlton's song "Hands On Me". (link)

Yeah that is pretty,(the Vanessa Carlton thing).
My musical knowledge was tiny until I started taking guitar lessons although I had been playing sax long before.

A minor

"D Minor is the saddest of ALL Keys, really.
I don't know why but it always makes people weep instantly. " -- N. Tufnel

lol like it. It's funny how we like some chords more than others.
I like D sus 4.

I like D aug or E minor.

Even though I play numerous musical instruments, I can only play them, I can't read music... However, I've prefected playing by ear... alot of people say it's a rare talent, but I think that adds to my uniquity... ^w^ I think the chord I like most is a D of some sort...

B minor is my favourite.