Ipod Classic
7th Generation

Ipod Shuffle
4th Generation
Ipod Nano 5th Generation
Ipod Touch 3rd Generation
160 GB 4 GB 8 GB 16 GB 8 GB 32 GB 64 GB
30,000 Songs 1,000 2,000 4,000 1,750 3,500 7,000
Classic
Touch
iPad
The iPad was the first tablet computer to find success in the market. The operating system is based on the iPod and iPhone, iOS. Its successful for the same reason as the iPhone. It's a completely functional computer in a small 10.1 inch form factor. Apple introduced several productivity applications built for the larger interface  including a word processor, spreadsheet, and slideshows. It's great to carry on a trip for browsing the web and watching a movie.  The current application catalog is not as large as the iPhone's but currently there 60,000 iPad specific applications. The 300,000 iPhone applications will also work with the iPad but in a small window. Here are some of the best iPad apps available.

Video:
Netflix - full access to their entire streaming library.
Youtube.
ABC Player - watch the latest episodes of shows on ABC.
ABC News - a globe like interface to see the latest news.
Vevo - music videos.

Sports:
ESPN ScoreCenterXL
CBS Sports Pro Football

Aggregators:
Pulse.
Flipboard - organizes twitter feeds and rss feeds into a magazine format.

News:
Wall Street Journal
AP
NY Times - full access to the newspaper in a format that easier to read than the website.

Shopping:
Amazon  Windowshop - browse through the best sellers in all their categories.
Amazon - full access to their site, easier and cleaner than their website.

Travel:
Kayak - easier to refine flight searches.

Local:
Yelp - full access to yelp, much better than their website or other mobile apps.  Integrates maps and pictures well.

Stocks:
CNBC - organizes videos and news around stocks, has some videos from the daily shows.
Bloomberg - great access to business news stories by sector or by stock.