[Corso]

Some are good, a few are borderline adware/junkware types... Over all each one is worth looking into and determining if it's usage fits your needs.

[Capwne]

This is very helpful I just converted from Google chrome to Firefox. Must say I'm enjoying Firefox much more than chrome.

[Chief Keef.]

This is quite useful, I may use some of these addons!

[Null Byte]

Revised list for you:
1. NoScript
2. AdBlock
3. VPN
4. (optional) HTTPS Everywhere
5. Set java security level to very high (via control panel)

That is all you need to stay secure. Seriously.