Here is mine:  (and by the way - all these work on my PSP SLIM)

- HellCat's Recovery flasher
- pspWrite by ZX-81
- eLoader - for the occasional 1.5 app
- PSPfiler
- Adhoc File transfer v.0.7 (wirelessly send ISO files to your friends @ 495 kb/s)
- All the emulators...
- Minesweeper (by: SG57)
- OpenBOR
- Deal or No deal
- Smash GPsp (homebrew smash bros.)
- Project 3 (really cool homebrew where you manipulate virtual falling sand)
- PSP Duck hunt
- Tetrabites
- BoxHead (SG57)
- Geometry Wars
- PSP Warp (picture warping app)
- SVC Player
- Light MP3
- VisMP3 v.01
- Bermuda CS9 (homebrew painting app)
- Bookr
- PSP Binary Editor (by: takeshi)
- UMDumper
- UMDrip
- Links2 (alternate internet browser)
- CTorrent PSP  
- Tipster Unzip/Unrar Utility
- Find My text coordinates
- ID Storage manger
- Key Cleaner
- NAND manager V0.5
- PSPident 0.1b
- PRX decrypter
- PSP PDA
- PSP Radio
- PSAR Dumper
- Todo en Uno PSP Hw v.10
- Firmware downloader
- CW Cheat Data Base Downloader
- PSP Tube
- PSPlayer FW4XX


that is most of them anyway...