General apps:
Acorn A lightweight photoshop competitor with a great pricetag and a beautiful interface.
DrawIt is a handy vector drawing app, which I use to make quick diagrams and simple illustrations. It has a few bugs related to grouping layers, but it has a clean, lightweight and intuitive UI.
VoodooPad it allows you to sketch out your ideas kinda like a wiki, really handy for brainstorming projects with multiple components
LittleSnapper is great for snapping websites, or taking screenshots and uploading them to forums and such if you need to discuss something.
Viewfinder is a great tool for quickly finding CC licensed pictures of a certain quality to use as stock photos in presentations by searching Flickr. If you’ve ever spent a lot of time looking for an image of a certain concept, this is a great tool.
Together is a terrific app that I primarily use to stash articles I come across on the web and want to save for later. It’s basically like a searchable file repository. You can stash text, documents, images, movies, sounds, web pages and bookmarks. It has a neat little panel that hovers along the edge of your screen when launched and you can drag website address bars into it to archive the article.
MarsEdit is a really cool blogging editor that allows you to keep a local copy of your articles on your Mac and then upload them to whatever blogging site you use. If you’ve ever written a long blog entry in the browser and hit publish, only to get a timeout error and loose everything you just wrote, this is your app.
Bodega an app store for OSX apps…kinda.
Concentrate lets you set up different environments so you can block out distracting apps and websites from yourself while you’re in that mode. So I could set up a “programing” mode and It won’t let me go to fluther.com until I switch out of it. It can do a lot more than that and it’s work taking a look at if you frequently find yourself getting distracted when you’re trying to get work done.
Speaking of getting work done, these are Web and Programming related apps that I like:
Versions is a subversion version control tool that’s incredibly well-done. If you’re writing code you should be using version control. Period.
Kaleidoscope is a file diffing app that lets you see the changes between multiple versions of a document. What’s really cool is that you can also use it to see changes in 2 versions of an image.
Others have mentioned Coda and CSSEdit
For programming:
Accessorizer a really amazingly handy tool for creating accessors in Objective-C.
BBEdit great text editor, although I’ve also heard good things about textmate.
Bwana is a little utility that lets you type “man:some_command” into your Safari address bar and see the man page in Safari.
Code Collector Pro allows you to save and organize code snippets you find yourself constantly using.
Feeder an app that generates xml for RSS feeds. It’s particularly handy for Cocoa programmers who create appcasts to keep apps up-to-date with the Sparkle framework.
Ingredients is a Cocoa documentation browser that’s really well crafted.
Lighthouse Keeper is a nice tool for interfacing with the lighthouse bug tracking web service locally on your Mac.
Fscript is a truly incredible tool that lets you poke and prod running 3rd party apps(including Apple’s) to see how they work. If you’re a Cocoa programmer and have never used F-script you should take a look at this video.