I hate spam. Here's how I try and keep it to a minimum:

My main mail account is my ISP account. I protect that email address very well - I don't give it out to just anyone, and whenever I have to sign up for anything online (except stuff like eBay, PayPal, and Amazon.com - those are companies I trust) I use my Yahoo.com free account instead. This really cuts down on the majority of spam, although I think my ISP has some filters in place too.

Yahoo has a pretty good bulk email folder, if the stuff is not directly addressed to me (as most spam is) it goes in there. I can empty that folder out without even looking at the spam. Whenever I have to provide an email addy and I'm not sure if a site will share or sell my info, I use the Yahoo account.