I have wi-fi only iPad.  Here are a few apps that I have on my machine.

Netflix

eBay

K-LOVE (klove.com)

Bible (YouVersion.com)

Google Earth

WeatherBug

Quickoffice

Alarm Clock (iHandySoft Inc.)

With Safari I access my Google Docs when I am in wifi range.  I also configured my Mail app to work with my gmail account.  I would recommend an Otterbox for your iPad, it has a great cover as well as a built in stand.

Need to start a thread on games sometime - I only have one that I have and use.