Apple Trailers App
TWiT (A video podcast network I watch, it's pretty niche tech oriented)
HDWallpapers: A great app with nice, hires images for your lock and home screen.
Infinity Blade I and II (Jaw dropping Hack / Slash)
Galaxy on Fire 2 HD (Beautiful Space adventure game)
Zenonia (Think SNES RPG)
Flipboard: This turns RSS feeds into a beautiful magazine type interface. I've tried others but always come back to Flipboard.
Comixology: A great app for reading / buying comics. With the new iPad they have added super high res versions of the comics and they are beautiful.
iBooks and Kindle App for standard books.
Keynote: I mainly use this for presenting keynote presentations I made on my Mac. You can make presentations here but I'm not fully comfortable with that yet.
iPhoto: an iOS version of iPhoto, in my opinion it's much better than the OS X version.
PSTouch: an iOS version of Photoshop
Evernote: I could go on for hours on how much I love evernote. For more on Evernote here are several blog posts I've made about it already. I'm starting to use it even more, to the point to where it's becoming my primary word proc and I use Pages to clean things up if what I'm writing will be used in some professional setting.
MindJet: A good mind mapping program.
Things: A good GTD Productivity app
iTAP RDP: A good remote desktop app. not flashy, gets the job done.
Airport Utility: great for administrating airport devices on your network.
WolframAlpha an iOS version of the WolframAlpha website. I like asking it odd ball questions.
TomTom: This is my favorite iOS GPS app, it has great voice directions, weekly OTA map updates, and realtime traffic. When traffic is bad in town I'll use it simply to find faster routes.