Definition of Humble:
1. not proud or arrogant; modest: to be humble although successful.
2. having a feeling of insignificance, inferiority, subservience, etc.: In the presence of so many world-famous writers I felt very humble.
3. low in rank, importance, status, quality, etc.; lowly: of humble origin; a humble home.
4. courteously respectful: In my humble opinion you are wrong.
5. low in height, level, etc.; small in size: a humble member of the galaxy.
By point 5, Yoda is humble
I'd say Raynar is pretty humble for a Jedi, as is Jaden Korr. Ganner is a great example of a Jedi who was not humble. Kyp would be another one. Both of them were pretty arrogant during the NJO. Using them as a template, the Jedi Masters like Yoda and Mace were certainly much more humble.
Yet to say Sith can't be humble...yeah, I don't think Sith can be humble. That goes against their code. Pride and arrogance are useful tools for Sith, so I can't see them tossing that away. By going down that path, Jacen opened himself up to arrogance.