Goodreads I use the Goodreads app and their web version to add book to my "to-read" list. You can also keep a list of books you've read, create your own list category like "business books", or explore other lists like "Best Books Ever", "Best for Book Clubs", etc.

PhoneFlicks - Netflix Queue Manager Although there is a Netflix app I like PhoneFlicks better for adding movies to the list of movies I'd like to see (aka my queue). PhoneFlicks also lets you view/add to your list of Instant Queue, and my favorite list is Recommended movies for me!

Grocery iQ this is my FAVORITE list making app. With grocery iQ you can manually add items to your grocery list but typing them in OR you can use the barcode scanner (I heart barcode scanners in apps) to add an item to the list. What I love about this app is that multiple users' lists can sync. So - my boyfriend and I have Grocery iQ and if he finishes the last of the juice he just scans the bottle so who ever goes to the store knows to buy more. I hate going to the store only to come home and find out you forgot one thing!

Evernote and of course we can not forget Evernote for list making. With Evernote you can make a list on your computer and then access it from your iPhone and vice versa.

Remember The Milk I've used RTM for to-do lists for quite some time and I LOVE it. It has push notifications if you set a deadline on a to-do item. Also repeating tasks are pretty great. I have a repeating task every month that just says "Rent" and it of course is due on the 1st. RTM pings me so I'm on time with my bills! I believe there are other sharing options on the web version if you want to make a honey do list and share it with your spouse but I haven't used that.

Plancast! I use Plancast to keep a running list of my upcoming event. I can easily add a plan to my list, and even share that plan to Facebook/Twitter from the app. I use Plancast for my public events - i.e. attending a conference or hearing a speaker because of it's social aspect.

Gist I am a big believer of having important information stored in multiple locations. So, I use gist to keep a list of my contacts and all of their contact info (including their social sites). There's a feature that allows you to add all of your iPhone contacts to gist with one button. My gist contact list contains my iPhone contacts, Facebook friends, and gmail contacts (and of course there is overlap between people).

Waterlogged - Drink More Water, Track Daily Water Intake, Use Remiders Are you drinking enough water? keep a list of how much water you've had today. quite simple.

TeuxDeux a clean and simple to-do list made my popular blogger swiss miss. You can manage multiple accounts, re-order to dos, and I love the drag and drop option.