Essential *must-have* software?

[Bod]

What software can you *not* live without? Software that has made using your mac so much easier, increasing workflow or productivity. Speeding things up, or just making your mac use that much more enjoyable.

I currently use

Quicksilver (first thing I grabbed after getting a Mac).
Skitch
Growl

I've just started using Dropbox (not *much* need for it personally though I don't think).

Also, just grabbed Typinator from MacHeist, that could be quite handy I think.

Any others? It can be pay or free

 

[Bod]

Ooh I forgot about LittleSnitch, I do already use that
I also use Quicksilver, Flip4Mac, (I think I uninstalled Perian as I use VLC, don't seem to need it).
Naturally use Firefox (but its really annoying me for the past couple of builds, with random CPU spikes / temp lockups)
I also use TextMate too

To look up

Leech, SizzlingKeys, VisualHub, Evernote, Pixelmator

I did use xSlimmer on my last install on my previous mac, but didn't use it properly.
Does it really make much of a difference?
I want some good software to speed things up a little...I'm a speed freak, so minor glitchey delays in something really nark me
I use Onyx for the occasional tweaky maintenance.
Oh and I also use 1Password...Everyone should have that!