For the development apps, more than anything these should not be taken as ringing endorsements… I like these apps, or, at the very least, put up with them. One thing that’s definitely hit me, being away from my former company, is that Java development is not nearly as nice as AppKit development. I’d much prefer to be digging around in Xcode, Interface Builder, Quartz Composer, Shark (a great performance analysis tool!), and agvtool (in /Developer/Tools/agvtool, useful for bumping version numbers in your application) than anything else. But you are what you, umm, get paid for, and so I don’t get to do that all that often these days.

UI Browser – This is an excellent tool for finding out what element is considered what in the UI, from an AppleScript point of view. Not being an AppleScript expert, myself, when I need to drop into it to do a certain task, or quickly manipulate data in another app, this thing has proved invaluable a couple times.

CSSEdit – I don’t even edit CSS all that often (thank the heavens), but I bought this app when I moved the Q.I. Software site out of iWeb (for the sake of all your eyes). I needed something more than vim to make the damn thing look nice, so I spring for this, which was nice enough at version 1.x, and is now 50 million times nicer in version 2.0. Nice job, guys.
SubEthaEdit – I liked this one when it came out, and still have a soft spot for it. I use it now the way I might have used BBEdit on the old Macs – spot html/code editing in which you only want a lightweight editor for the job. The collaborative features I’ve used with dev teams in the past, and are handy to have.

Accessorizer – Less useful for Java accessors, especially if you’re, at heart, an Objective-C coder and want to keep similar method signatures between your two types of classes, but this is a great tool for Cocoa developers, above and beyond the built-in Script Extras you can add to Xcode (which are very handy, in and of themselves, and live in /Library/Application Support/Apple/Developer Tools/Scripts when you have them installed… and I think might be installed by default now… if not, they were always in the /Developer/Extras folder, or thereabouts).
eclipse – IntelliJ seems slightly more polished, and the conflicts between versions of the plug-ins (WOLips) and itself are maddening, but this is the world we live in, now. Oh well. I like the Command-Shift-G shortcut to find references to a method you have selected, and the refactoring stuff is nice…
TextMate – It’s a nice enough text editor. I like the tabs, wish it could remember state of directories I’ve had open (like Rails app directories and the source files I’ve been editing), and it also seems a bit sluggish, at times, to me (could just be me, though).
OmniPlan – Used this for a few Agile-like sprints while it was in beta, and my wife uses it… I like it. I’m sure I’m not using it nearly to the best of its capabilities, but then I’m also the eejit that had himself scheduled at 800% at Sportal with MS Project… doh. Maybe I should avoid project planners, then.

All icons copyright or so to their respective developers.