Deluge
I only found this <viewtopic.php?p=138947>, so here we go:
A built-in filter (plugin?) for torrent names (and possibly filenames) to automatically change names based on filter rules would be quite nice, e.g. apply RegEx filters when torrents are added or finished. This would be usefull to remove bs like 'www.Torrenting.com - ' from torrent names or change s01e03 to 1x03 notation and such.