RoboBasket has a slick, simple interface for setting up filters, and offers complex filtering options allowing for fine-grained control. Path recursion is set on a per-folder basis rather than per-filter, requiring a workaround, but generally we like this tool - albeit it isn't free. See all software reviews.
If you like the idea behind DropIt but are after a more robust, commercial tool, you should take a look at RoboBasket. At its core, this £13.59 inc VAT utility works in a very similar way to free DropIt: You configure file handling rules, and set it loose to enforce them on your messy folders and create order. See all software downloads.
The biggest difference between the two (other than the price) is that RoboBasket has a much nicer interface for configuring filters, allowing for fine-grained control. File conditions and actions are shown as a vertical bar on the right side of the window. If you want your file to apply to all ZIP files, just drag the "Extension" condition onto the filter, and set it to "ZIP". If you want it to only apply to old ZIP files, drag the "Date Created" condition onto the filter and set it accordingly. In this way you can build very fine-grained conditions that apply to specific files, but the filters remain easily readable and manageable. The same goes for operations: You can both move files and rename them, for example.
The only point of confusion I had with RoboBasket had to do with recursive operations: You can have RoboBasket apply a set of filters to a folder and all of its subfolders. I had it move all Zip files in my Downloads folder into a Zip subfolder (so, Downloads\Zip). I then ran it again on the Downloads folder, but recursion made it do something silly: It created Downloads\Zip\Zip, and put all the zip files there. Every time it ran, it buried my Zip files one level deeper in the file hierarchy. This is because recursion isn't set on a per-filter basis (as would have been sensible), but on a per-folder basis.
There's a workaround, though: You can create two sorting profile for the same folder, and set just one of them as recursive. So you put all of your recursive rules in one profile, and all of the others (say, file moving operations) in another. It's not elegant, but it's workable.