Thanks for sharing your experience!
I'd like to add
Butler - small app that sits in the menu bar and adds just 1 icon, but under this icons is whole bunch of useful stuff -- just press Ctrl+Space and start typing appliccation or Contact person's name, and it will find it for you in a second! It has several clipboards which can save their content upon computer shut down or restart, it has Application list, etc etc.
Some other stuff I've found useful:
Accordance - Mac Bible software. Gradual upgrade is also possible.
Audio Hijack / Hijack Pro - grab audio from any application and record it!
Apples to Oranges / iUnit OSX - all kind of conversions.
Captain FTP - FTP client with Randezvous support.
CocoaMySQL - extremely good MySQL frontend with GUI, work with MySQL tables like in Excel - click in the cell and edit it's content

Curio - store all your creative ideas for the particular project in one place.
FileWrangler - file batch renamer.
iBackup - free backup utility. Twice saved me from real disaster.
Imprint - print envelopes and labels from your Apple Address Book. Can save results as templates.
MacSword - Mac Bible software for free.
PlainClip - removes formatting from the text in Clipboard.
MacFamilyTree - geneology software. Looks very promising.
Mellel - very good text processor for technincal documentation. Actually for me it's MS Word substitute. I am fully satisfied

Jumsoft Money - very simple (too simple?) money management.
MPlayer OS X 2 - real Mac-like media player - for those who don't like QT.
NewsFire - the way RSS feeds were meant to be read.
NetNewsWire - another good RSS reader.
OmniDictionary - free dictionary, can be made also into offline dictionary.
PhaseOne C1 - convert digital SLR camera RAW files into TIFFs or JPGs.
skEdit for PHP and HTML editing.
PrintWindow - print folder and file lists, directory trees.
Salling Clicker - control Keynote presentation or iTunes from your bluetooth mobile phone.
SideTrack - give more power to your PowerBook's trackpad!
Skype - talk to your buddies over the Internet for free! Or call to the landlines for very cheap money.
SlimBatteryMonitor - color your battery info in the menu bar for iB or PB.
Steel - save all your passwords in one password-protected file.
StickyBrain - great place to store all kind of useful info. Just select any text or pictures, press Option-Command-C and it's saved in indexed database.
Synergy - control iTunes from the menu bar.
TimeOut! - for those who forget to excercise while sitting at the computer.
VLC - everyone knows it! Great media player, just playlist isn't as good as in WinAmp or MPlayer OSX.