+1 for Crayon Filter & Frohmage

Some more good freebies you should try:

Tone2 BiFilter (last freeware version):
http://www.gersic.com/plugins/hosted...lter_v1_61.zip

Devine Machine's Minion:
http://www.gersic.com/plugins/hosted/Minion.rar

The good old ProSoniq's NorthPole:
http://oldsite.prosoniq.com/pub/freebies/pc/NPOLE.ZIP

Christian Budde's Rubberfilter:
http://www.savioursofsoul.de/Christi...bberfilter.exe