There's a lot of widgets out there, and a lot to choose from. Personally, I like ask.com, I have a certain fondness for Jeeves - maybe because he was there when I first started seeking answers online and offered an "easy" user interface (ok so Jeeves also led me to horizons I was not seeking for, but thanks to him I learned a lot of things I would probably ignored otherwise).
I like the graphics of this Immediate Answer - finally something that isn't a box or simply rectangular -- it is Immediately visible on my dashboard and Immediately gives me answers (pardon the puns, I can' resist!!)
Oh, I took the time to go and see your other widgets - wow what a selection and what a breadth of information. Do you ever stop? lol. As a graphic designer, let me just say that your NASA widget is well-crafted front and back. A lot of widget developers don't take the time to polish the flipside but you really did- the graphics are superb.. which explains why it is the featured widget on graphicreporter.com