ihacksrepo.com/ has tons of winterboard themes and cracked cydia apps.
repo.insanelyi.com/ also includes tons of winterboard themes and alot of tweaks.
Sinfuliphonerepo.com/ this is probably my favorite source becasue it has the best cracked cydia tweaks.
apt.123locker.com/ has some roms for GPSPhone.

Dreamboard is a complete ipad theme applier. it takes your entire springboard and turns it into something beautiful. There are tons of dreamboard themes you can download from cydia.

RetinaPad enables retina display for iphone apps running on the ipad. it has support for most retina capable games.
iFile is a file manager and viewer. you can use it to copy, paste, rename, and move files. also can be used to hack some ipad games.
Zeppelin takes the old "iPad" carrier logo and can change it to many things including the " Nike Swoosh", "Storm Trooper" or an " Infiniti Logo".
GPSPhone is a fully featured emulator for gameboy advance.
Pandoraskip lets you skip unlimited amount of times instead of the 6 per hour allowed by the pandora app.