Which kind of phone should I get?

I have narrowed my choices to BlackBerry® Curve™ 8330, Samsung ACE™, and the 8830 by BlackBerry®. What are your opinions? Should I consider another phone? I have service with Sprint/Nextel and they've been pretty good. I like going online and using messengers on my phone so i'd like to stick to a pda/smartphone. Feel free to take a look at this link: a href="http://nextelonline.nextel.com/NASApp/on..." rel="nofollow"http://nextelonline.nextel.com/NASApp/on…/a