Apple → New to OSX - software suggestions?

My girlfriend flew in to visit and after being staunchly anti-OSX for a while, I've managed to convince her to give it a try (I'd like to thank win8 for its hand in helping with this - my convincing consisted mostly of "that's part of why I ended up going with a MacBook" comments). We went from "I'll try yours" to her buying a new laptop (after us talking about her needs/uses, and then her using the MBA/MBP/MBPr in the apple store for first hand experience for a while to make sure it was the right decision for her)! Anyway, she's now the proud owner of an i5/8gb/256 13" MBPr (same as me!)! After the initial couple hours of learning the differences she seems to be pretty pleased (and so am I because I won't have to hear her get upset about windows crashing on her) with only the occasional frustration since she was so familiar with the workings of Windows.

This got me thinking, though: What free or relatively inexpensive apps do you guys have on your computer that you feel are pretty indispensable? I use scroll reverser (so my external mouse scrolls the normal way even when I use "natural" setting on the touchpad) and f.lux, but thought this would be a great opportunity to see if I'm missing out on anything else! Any/all suggestions appreciated!

Just by the way, trying to rely on the stability of OS X bit me in the behind when my wife's laptop's logic board died after two years. Regardless of how unrelated it was to OS X, she ended up thinking Macs are just as bad as PCs. Now I convince people with the ease of use and customer service angles.

Pixelmator is a nice image editor. Reeder for reading RSS feeds (if you are into that sort of thing).

I actually find the default set of Apple provided tools very comprehensive. The 3rd party software ($ or $$$$$) I have installed is:

For work:
-Adobe CS6
-Office 2011
-Matlab
-OmniGraffle
-Papers2

For fun:
-Reeder
-Subler (for adding metadata to DVD rips)
-Handbrake (for creating DVD rips)

I still use Open Office, which is free.
Handbrake, for converting video's (or DVD rips)
Transmission if you need to torrent.
CrossOver for Mac if you need to run any Windows software and you don't want to run Windows via Bootcamp or Parallels or Fusion. CrossOver does not require Windows OS to operate.
unDock Now, which disconnects all connected devices.
Grand Perspective, which shows you all the files you have on your Mac.

Thanks, guys!
Daemon - Luckily she's pretty computer savvy and knows the difference between software/hardware in case anything hardware goes out! ...I don't think that would *help* by any means, though.

if she has a laptop then definitely Coconut battery (free).

The thing that it does that is invaluable is shows the current battery draw in watts and also logs the capacity and cycles against a date. If you leave tabs open with stuff running what should be 9w can become 15w or 20w. Adobe plugin is the usual suspect. If you know you're going to be using it for several hours away from power it is useful to know for sure you're not draining the battery faster than you expected.

There is also an online compare thing so in a year you can benchmark the capacity left against the average of other owners of the same hardware.

Thank you! I used to use that on my last macbook and haven't thought to install it on my new one... I will definitely be grabbing that again (especially since I'm running Creative Cloud)!

MenuMeters. Its le shiz.

Here's the software I make sure to install of my Macs. It's a combination of development tools, audio tools, and general purpose utilities:

Adium - Multi protocol chat client (AIM, IRC, Facebook, etc)
Audacity - Multitrack sound editor
DiffMerge - Visually compare the contents of two files (like xdiff, winmerge, etc)
GrandPerspective - Visually see the file sizes of files on your hard drive
ImageOptim - Remove metadata from photos (for example, strips off the GPS and other stuff from JPEGs taken with your iPhone)
Keka - Create ZIP/RAR/7zip/etc files without the __MAC_OS_X resource fork crap
Max - Accurate CD ripper and audio converter, my go to for FLAC - ALAC - AAC - MP3 conversions
NameChanger - Rules based file renamer with regex support
Tagger - Audio tagger (Author, Title, Album, etc) for multiple audio types (FLAC, ALAC, AAC, MP3)
TextWrangler - Advanced text editor
Transmission - Lightweight bittorrent client