I am able to transpose them so that won't be a problem for me.

e.g. C Dm Em F G Am Bdim
Csus Dsus Esus Gsus Asus
D7sus E7sus G7sus A7sus
Bm7

I can't think of anymore, but I would like a full list if possible...would help me a lot

You can play *any* chord in the key of C. If you hold the chord for a long time, it should match the melody tone(s), but if you play the chord quickly it doesn't.

Maybe you'll find the charts on this site useful:
http://www.chordmaps.com/

I think i'll agre with what Matthijs said, for instance in the key of C, you could think of a Bb chord being a bVII, but in classical theory I would suppose this would be called a V/IV.

If you played a Db chord in 1st inv., you would have a Neapolitan sixth chord in C major. I'm thinking if you added a 7th to this, you could use this could to modulate to Db form C major. I'm not sure though.

If you play an Ab7 chord in C major, then you are really playing a Ger.6 chord (German 6), which normally resolves to a V chord. This chord is usful for mdulating as well.

In the Key of C (speaking diatonically of what combinations of notes produce chords from within the spelling of the C Major scale (or relative A minor) there exists only white notes in the chord based on the scale - No #'s. No b's by definition of the Key Signature. So don't add alterations.

Root positions are alternating letter names.

C - D - E - F - G -A - B - C are what we have to work with.

I CEG - Major chord
ii DFA - minor chord
iii EGB - minor chord
IV FAC - Major chord
V GBD - Major chord
vi ACE - minor chord
Vii BDF - diminished chord

Definition of:
"Major Chord"
"Diminished"
"minor"
Augmented doesn't apply here as it requires the 5th tone of the chord to be #'ed when writing it on music paper.

6ths can be added, 7ths, octaves.

This is the way I see it.

Of course, any notes of the 88 can be played at one time as long as you can reach them with your hands and fingering. You can work with any combinations (spellings) but the question was "in the Key of C" meaning using the Key of C signature.

[Insert 'infinity' symbol]

Well I should say then, what chords can I play in the key of C without having to use any black keys?

Like I posted in the first post some examples...I just want a listing of ALL those possible chords.

Bm7 includes a black key.

Have fun finding chords with this tool:
http://www.pianomagic.com/PMMOcourse/virtualpianochordfinder/chordfinder.html

I'm confused by what you are asking and the answers we are reading.

Are we speaking diatonics?

If the question is what chords can be played from the C Major Scale: you would need to use C D E F G A B C (all natural notes) to form triads on, yes? (As per my posting above all written in root position). (Then you may want to count inversions of those)

Add the 6th degree to the root of the chords I posted before,
Add the 7th degree - major 7th - minor 7th (black keys again)
8th degree would simply be the octave.

Any triad of 3 adjacent spaces or 3 adjacent lines (music staff) is a root chord. All root chords can be major, minor, diminished, augmented. Then you can add a 6th to the root chord in it's major, minor, diminished, augmented state. Add a 7th to the same root chord doing the same alterations.

If you add black keys to the mix, you are not in the diatonic scale of C Major which uses only the notes appearing in the scale in question.