Jailbroken 1.1.2.
Reasoning for me is that 1.1.3 is a superficial update and to me not worth the hassle and likelihood that I will have problems.
The primary reason for me being on 1.1.2 is that I write my own apps which increases the usefulness of the device greatly. For example, I am just completing an application that allows me to download files from EasyNews, complete with download queue and ability to pause and resume downloads. I'll be releasing this along with an app that allows you to do the same thing but with any website - simply enter the address and it will display links on that page you might want to leech. Clicking on each link will add it to the download queue and it does the rest for you. Perfect for me here at work as I can leech via a wifi hotspot nearby while in the office, and sure beats lugging in my laptop (with coworkers wondering why I am mucking around with that instead of my work PC).
Personally I feel sorry for those who just try other apps and dismiss jailbreaking as useless. Either they can't or won't code their own apps that are useful for themselves personally. Being able to do that beats any situation.