Is Daenerys Tagaryen good?

I'd say that is relatively subjective. For the most part she is good and if she were to become the Queen of the Seven Kingdoms she would probably rule wisely and kindly towards her people. However, her desire to regain the throne is primarily motivated by revenge and if she had the capability she would wage a war to regain the throne for the sole reason that it was once held by her family and "rightfully" belonged to them. One might argure that her willingness to go to war and see thousands die in order to place a Targaryen back on the Iron Throne might not exactly make her the "Mother Theresa" of Westeros.

Also considering how brutal and antagonistic her father were i would say that the others weren't wrong to steal the throne. To truly understand and answer this question you would have to read the game of thrones lore.