I think you'd need to define "good" to get a usable answer to this question. What features are you looking for? How many people will be using it? Have you looke

I think you'd need to define "good" to get a usable answer to this question. What features are you looking for? How many people will be using it? Have you looked at anything already? If so, what did you like/not like about them? That said, check out Redmine and Tiaga and possibly Kanboard.