Currently your options are diametrically opposed. On the complex side of things there is DotProject. This is the only web app that I have used that has such a high barrier to entry. DotProject is the only pm software I have ever used that requires the developers to create a company and has dollar value fields before you have even designated your projects intentions. On the other end of the spectrum are apps like BaseCamp, Assembla’s bug tracker and project pier, all of which are just too simplistic. Assembla’s system is a step or two towards the middle of the spectrum, and that’s because it allows you to set up relationships between tickets. Trac is just a pain, and for the record I really hate that all these new SVN hooks require python… hint hint.
Where is the PM app that allows me the freedom to create ad hoc projects and the ability to get into the nitty gritty where I feel it is necessary? Maybe a PM app based off of the way Mantis works? In fact the only thing that I would like Mantis to add is the ability to set up relationships with its tickets. After that its about as far as it can go without being GManager.