In my opinion the best is still pages. It's clean, uncluttered and easy to use, has more than enough functionality for everyday use and also has useful stuff like iCloud. If I were you I'd work out what you need to use the word processing for, and then read some app reviews from the various apps on the app store and decide which one best meets your needs. I rarely buy any sort of app nowadays without doing further research, might sound silly, but I haven't bought a naff app in a long time.
Sent via iPF from my iPad2 iOS 5.1.