Favorite firefox add ons and plug ins (again, sorry :( )

Last month my firefox fried, yesterday the motherboard on my Dell croaked and so I am finally on my new laptop,lol. So yes, I'm asking again because I can't remember them all,lol. There is one with the colored tabs, there is one where I can verify if sites are safe (uses a big green Q if they're safe) and a few others.
If you'd all share your faves i would really really appreciate it