JunkBuster works well, I use a modified version and since the source is available it's easy to modify.
Point is, with a proper blocker file, all kinds of crap are blocked, and there's a window so you can see what pages these nefarious pages are accessing.
Most folks would be amazed at the shit going on behind the scenes.
As for redirects, block them, not much that can be done except once a site that does that is identified, chuck 'em in the blocker list and move on. They don't deserve anyone's time.
PeerGuardian is useful too. It'll block sites at the IP level and they have a whole lot of freak sites that are blocked.