An easy to use XDCC Browser. This addon will list all the XDCC ads for you, and put them nicely in a dialog. You could search these ads, and request them. And there's a good requesting system, so you can rejoin people in different servers, and resume the request from them. And of course you can request more then one XDCC from every user, and it will download them in the order you want.
This script supports multi servers, and multi mIRC windows via DDE ... so if you have a script that also uses it's own DDE then it might have some problems...
This script supports every XDCC script and advertisement.
There's also an option for online search that searches in XDCC search pages.