Interval            Consonance/Dissonance       Waveform                        Character
Unison             perfectly consonant                    simple                     plain
Second               dissonant                            quickly pulsating       wants to be resolved
Third                 consonant-                                pulsating            pleasant, richer
Fourth               consonant                                 stable                 pre-classical connotations,  sound slowly cycles
Fifth                   consonant+                              stable         classical connotation, halfway between tonic/dominant
Sixth                  semi-consonant                  pulsating     less frequently used, harder to identify, not simple like 5th
Seventh            dissonant                       pulsating quicker              wants to be resolved, unusual interval
Octave          perfectly consonant      more complex than unison,stable               richer than unison
Ninth            semi-dissonant                       pulsating                                   more pleasant than second
Tenth            consonant                                   stable                                     complex, somewhat similar to third, happy

Tuning Ratios for Just Intonation:

Unison= 1:1 Second=9:8 Third=5:4 Fourth=4:3
Fifth=3:2 Sixth=5:3 Seventh=15:8 Octave=2:1

(here is my new music blog which focuses on things similar to this.)