I'm addicted to the ipad. Things I use every day:
Facebook - duh
Safari - internet browser - for TEG and wunderground weather - duh
Zite - awesome article gathering app - you tell it what general topics you have an interest in, and it downloads articles. Then as you read them, if you tell it "Yes I like this" it gets more articles with those keywords, and you can also tell it "No I don't like this one" so it won't get articles with those keywords or from that source anymore. LOVE it.
Zillow - I house shop every day, just for fun.
Pocket - it stores those wonderful articles you read in Zite (or other apps) that you want to keep to refer back to. Wonderful for recipes, garden ideas, etc.
Pinterest - occasional visits.
I have 3 map/travel apps - you'd think one would suffice but I use them for different things.
GPS HD MotionX - mapping software that keeps track of data on your movements - good for mapping bike rides or hikes
Maps - I think this is the Google app, I use it for navigating in cities or while driving - the maps are clean and easy to read, but don't work offline
Topo Maps - this is for backcountry use when there's no service. You download the map for the area you are going to be in, and can access it even out in the boonies, and it shows you as a little bouncing GPS ball. This has saved me from taking wrong turns while hiking or biking a number of times. If I'm not sure which way to go, I check the app, see where my bouncing ball is, then walk 1 way maybe a hundred yards or so, and check the app again to see if I'm on the trail I wanted to be on.
GoSkyWatch - ID app for stars and constellations, so fun! You point it up at the sky and it shows you what you're looking at.
Pandora and TuneIn Radio - streaming music
I would have tons more apps if I had a newer device. This one is so old I can't update the operating system anymore, so a lot of newer apps don't work. There's an apple photo editing app I would have, as well as some bird ID apps. Someday soon...ipad mini with tons of storage!