A healthy installation of Ghostery, Facebook Blocker, and Flashblock has a fair amount of overlap, but seems to improve my web experience a great deal.
I used to have AdBlock in the mix, but I develop web sites, and sometimes you actually need to have a div called "ad" or "adv" when you're integrating other people's code. It's hard to develop sites when those divs just vanish.
That's why it's nice to have multiple web browsers installed, or have multiple accounts or VMs with their own browser configurations, leaving your main personal browser config exactly how you'd prefer to have it.
I used to have AdBlock in the mix, but I develop web sites, and sometimes you actually need to have a div called "ad" or "adv" when you're integrating other people's code. It's hard to develop sites when those divs just vanish.