Inspired by Scott Hanselman's Ultimate Developer and Power Users Tool List for Windows here's a list of tools I use (in contrast to Scott's list, mine is more geared towards OSX).
General System Apps
UninstallPKG - The missing OSX uninstaller, $10.
Alfred - Launch apps, view contacts, perform arithmetic, and more from a simple hotkey. Free with a paid add-on.
Flycut - Clean and simple clipboard manager. Instead of overwriting your last copied text, you'll get a history of text you copied. You won't believe how many times you'll paste something you copied hours before and wonder how you lived without this!
Slate - Super powerful, incredibly customizable window management application. I've published my puny config file in a gist (if you find, like I did, that the default config conflicts with a lot of your existing hotkeys this could be decent place to start but there's a ton of options I haven't gotten around to configuring)
The Unarchiver - Handles more formats than the native Archive Utility. "Supported file formats include Zip, Tar-GZip, Tar-BZip2, RAR, 7-zip, LhA, StuffIt and many other old and obscure formats."
Airmail - I've tried a lot of email clients and didn't love any of them until Airmail. It's beautiful, fast, and has some great features like a Markdown editor (the default on my machine)
Brew - "The missing package manager for OS X"
brew install zsh
iTerm2 - Free (donationware) replacement for the default Terminal app. It features split panes and both standard and drop-down style access. There's also a website with a bunch of themes (I like the Monokai based ones)
TotalTerminal - if you're just looking for a drop-down style terminal, here's a great option. (I'm exclusively using iTerm2 since it includes this functionality plus has lots more features)
Sublime Text - My code editor of choice.
Kaleidoscope - Truly beautiful merge/diff tool. Supports text, images and folders.
Charles Proxy - HTTP proxy for debugging. I haven't found a lot of choices on OSX. This one is $50 but well worth it.
SpiderOak - You really should be backing up all your data. Seriously, if you're not doing that you should stop whatever you're doing and deal with this right now. I looked at a lot of options and decided on SpiderOak because
- believe it or not, a lot of backup services don't encrypt your data, spideroak does
- the encryption happens client side - meaning on your computer before it's sent over the internet to their servers. they even encrypt file and folder names!
- native software (not java)
- reasonable pricing - $100/yr per 100gig
- deleting a file moves it to the trash - that's important because you don't want to accidentally delete things from your backup
Wuala - I moved to SpiderOak from Wuala because I liked the software more. Wuala's built using Java (already a turn off) and seemed complicated for my use case (the software can sync data between machines but they differentiate between backup and sync). But Wuala also offers client-side encryption and works well so it's a valid option too.