I’ve been asked a few times why I like jailbreaking so much and I constantly am telling people what apps I use. Just to keep everything in one place. Here are my top apps/tweaks that keep me coming back.
These are listed in alphabetical order
Activator
Activator lets you customize any button push, gesture, etc. into something that makes sense to you. For me there are 4 shortcuts that I use frequently

• Hold volume down (while phone is on) = Compose new tweet
• Hold volume up (while phone is on) = Show contact favorites
• Triple press home button (while phone is on) = Open camera
• Triple press home button (while phone is locked) = Play/Pause

Here’s a quick video I found that shows some of the settings and how it works.

Browser Changer

Allows you to change the default web browser in iOS (Mine is set to Google Chrome)

Chromizer

Adds some gestures to Google Chrome

Data Monitor

Lets me see how much data I have used per day and per month on wifi and 3g connections.

F.lux

Changes the screen hue based on the time of day. You specify what type of lights you use and it automatically adjusts.

Five Icon Dock

This one does exactly what you’d think

FolderEnhancer

Puts folders on steroids and really customizable. This was the 2nd jailbreak app I bought.

iFile

Just a file browser, but if you pay for it you also get Dropbox syncing etc.

NCSettings

Like Android toggles in the notification center.

OneByOne Contacts

Lets you swipe to delete contacts like webOS used to.

PasswordPilot

Automatically enters your App Store password

PdaNet

PdaNet has been around forever and the only way you can get it on your iOS device is with a jailbreak. It’s a one time $15 fee but well worth it if you tether a lot and don’t want to pay the $15/mo charge to the carrier.

Pull To Dismiss

Gets rid of the keyboard when you don’t want it. Easier to explain in the video.

ShowCase

I just found this one and it fixes a HUGE annoyance I’ve always had with iOS. Check out the video.

Silent Rington

Give you a ringtone that doesn’t make any noise (just vibrates). It’s great for an alarm when you don’t want to wake anyone else up.

Siri Toggles

Turn on/off wifi, bluetooth, etc. with Siri. This functionality is built into iOS 6, but I’ve had it in iOS 5 for quite a while.

SmallBanners

Makes the notification banner smaller.

SMS GV Extension

This seamlessly integrates Google Voice into the default SMS app. Here’s the website for more information.

SwipeSelection

Adds gestures to the iOS keyboard that I wish every keyboard had.

SwitcherMod

Allows you to customize some features of the app switcher. I use this to always show the close X on apps.

Switchy

Makes the app switcher 2 rows high and adds other customizations

WiCarrier

Show’s your currently connected wifi network in the status bar. More info at iDownloadBlog

xCon

Hides your jailbreak status for some apps.