I've started, finally, clicking on unsubscribe links, especially for reputable-looking emails that I don't want anymore.
The old wisdom was that unsubscribe links were a trap, and clicking on them would cause you to get more email. This is still true for lots of true spam, but it's not true for most legitimate newsletters and other online marketing methods that exploded several years ago.
I expect that several years ago I ordered a product from a site (and forgot to 'opt out' of the site newsletter), and then I apparently got signed up for all their friends' mailings as well. But these days, when you're a legitimate internet business, failing to respond to unsubscribe requests puts you in a lot of trouble with the government. The CAN-SPAM act put a stop to this kind of trick, and it seems safe now to 'unsubscribe' for a good percentage of real email marketing. I've now done it for about 40 different sites and I'm getting a 90% success rate.
The good sites will log you in on clickthrough; the bad ones will make you remember a password to manage your account (which I never do, and I give up). However, they're also required to respond to email removal requests and requests by mail, so if you're really persistent, the password foil isn't enough.
This has cleaned up my email inbox more than I can say.