I can second the Transmit
recommendations. Transmit is made by a company called Panic, and really all of their stuff is worth checking out. Best software on the Mac.Quicksilver
is totally required and is much, much more than just a "launcher application." You can use it for searching, moving, copying, deleting, renaming, uploading, tweeting, controlling iTunes, navigating your filesystem and pretty much anything else you can think of.
I also use Adium
as my IM client.
For IRC clients, the best choices are Linkinus
(shareware but very reasonably-priced) and Colloquy
(less lovely, but freeware).
Screenshot applications are frankly totally unnecessary. You can take a whole-screen screenshot by pressing cmd+shift+3, drag out an area to capture by pressing cmd+shift+4 and, well, dragging, or take a screenshot just of one window by pressing cmd+shift+4 followed by the space key and clicking on the window. Those functions are built-in and save the image as a PNG to the desktop, which is very convenient.
Firefox is not worth getting on the Mac. It might be fast on Windows, but it isn't here. You either want to use the standard Safari, or Camino
, which is built on Mozilla specifically for the Mac and seems to be the best option, speed- and standard-wise.
Like Arne says, it might be a good idea to use the function keys as standard keys, giving you easy access to the Spaces (F8) and Exposť (F9-11) shortcuts, as well as F12 for the dashboard. You then access the brightness, volume etc. controls by pressing the key + fn.
I also use smcFanControl
and can vouch for its usefulness and general goodness.
EDIT: Got the screenshot shortcuts wrong -_-. I only use them on a daily basis...