POPSLOADER - Load PS1 games in different firmare modes, for maximum compatibility.
PSP States V2 - Savestate on any PSP Game. written by Dark_Alex, updated for 5.50 GEN by Total_Noob
CXMB Plugin - A plugin that allows you to load .CTF theme files on your PSP.
Game Categories V9 - Allows you to separate your games into categories in the XMB.
Hold+ V4 - A plugin that saves power while listening to music. It will turn off the lcd screen, and under clock the cpu with the flick of the hold switch.
DayViewer NEO - A plugin that displays the day of the week on the XMB.
Ultimate VSH Menu Revised (by Total_Noob)
A replacement of the standard VSH Menu with many more features added.
Davee's Unlimited Character Version/Mac Address Spoofer v4 (updated for 5.50 GEN by Zer01ne)
Spoof your firmware's version and MAC address to whatever you want it to be via two text files.
Custom Firmware Extender 3.1 (by Cpasjuste)
Change your CPU Speed, brightness, take screenshots, load extra plugins, enable/disable RemoteJoy, use USB Mode, listen to music, anytime either when in Game or XMB through the Custom Firmware Extender Menu with a press of a button combo.
Preview Contents Hidder - This is a plugin wich allows you to hide ICON0.PNG, ICON1.PMF, PIC0.PNG, PIC1.PNG and SND0.AT3 of UMDs, PBPs and savedates
in the XMB menu. So you can browsing/loading faster. Or maybe you wouldn't to see the background image
SVCapture Plugin - A plugin that allows you to take screenshots or video capture the screen to a .gif file. As of 5.50 GEN-B2, SVCplayer is not working, but the capture plygin itself is working fine :D
Audioboost v0.0.2b
This plugin raises the volume limit of your PSP's audio output on both speakers and headphones.
(I personally tried this myself and it definitely increased the sound output through my PSP's speakers and earbuds and not to a point where everything sounds distorted)
SimplySaver
This plugin allows you to save files you download from the PSP's internet browser anywhere on your Memory Stick.
(For example: You can save an MP3 into the picture folder, an MP4 movie into the music folder, and save other files anywhere)
ResourceHidder
Similar to what Preview Contents Hidder does, but with more options such as skip the gameboot & the PSP logo on the gameboot.
hud ver 2.2 plugin
works fine on GEN add that, its a very useful plugin :D it gives a heads up display of things like your battery the time, CPU etc also allow you to take screenshots
FUSA SD
and for those how have slims, this plugin still works on GEN as well the fusa plugin is designed to play games on t.v in full screen, very cool