Based on Max Gallo's Cesar Imperator, he was a complicated personality (like almost everybody) not purely good and evil. The problem is that your question suggests that there are unchanging historical standards who is really a bad guy violent dictator and who is a good guy. Let me just say that he was not always picky with his methods, as nobody else was, and his motives suggest both selfish seeking of glory and a not selfish actually wanting to help Rome.

But I guess if I wanted to judge Caesar harshly, I wouldn't even have to care about what he did to Romans. I haven't added up the the figures in the book but the amount of non-Romans he massacred or sold to slavery (and I mean civilians, not battle casualties) looks very staggering.