Up until now, I've been rather lucky with spam. I've not had any comment spam (yet!) nor do I get much email spam, and what I do get is handled nicely by my filters.
...I didn't mention my contact forms though, did I? No... the ones on this main site are fine for the moment, but my design site's just been hit HARD (the same script is used on both sites). Some bot went through every single page and spammed the contact form like crazy. I edited the form script (Dodosmail) really thoroughly to stop this kind of thing happening, specifying pages the form had to come from, variables that had to match a list etc. Banning the IP the form came from is just about as useful as replying back to the address that "sent" those forms telling them I don't want their services or whatever since they change every single time and are probably fake anyway.
I'm sick of it. I don't want to have to take the form down but I might have to since it's being abused so much. Grrr argh bah stuff. Spam bots suck.