Here is a good list of chords that I play all of the time. It is handy in knowing this when playing Lead Sheets or the Fake-Book Chords. Notice the symbol next to the letter which tells you what type of chord.
Major : 1 3 5 : Example (C)
Minor: 1 b3 5 : Example (Cm)
Diminished : 1 b3 b5 : Example (Cdim)
Augmented: 1 3 #5 : Example (Caug or C+)
Major 7th: 1 3 5 7 : Example (Cmaj7)
Dominant 7th : 1 3 5 b7 : Example (C7)
Minor 7th: 1 b3 5 b7 : Example (Cm7)
6th: 1 3 5 6 : Example (C6)
9th: 1 2 3 5 : Example (C9)
Extra Note >> b = flat and # = sharp
I also like to use suspensions where I will play the second tone or the 4th tone and then move that note to the 3rd tone to round out the chord. I interchange those all of the time to give the song more color and a different sound. This keeps me from playing the same song the same way. Changing up the chord and inverting it works well also.