Lee Odden is running a poll on search marketers' favorite keyword research tools.
I do use and/or recognize most of those listed therein... A couple of them I've never heard of despite how I normally keep about 30+ tools on-hand for keyword research and analysis specifically.
I don't have a hard favorite, but the one I'd pick if I were limited to using only one (I normally don't settle for that for any given project), that one is in there... I won't say which it would be but I will say it's not the one leading in the poll, also it probably won't be the one to win which is kinda how I'd like it. Though many tools have redundancies in between my opinions here are pretty strong. On one hand I'd love to see certain tools get more developed, on the other if all SEOs were standardizing on them that would ruin some of the fun.
Anyway... Right now what I could really use would be a great keyword research tool for Chinese engines. Short of Baidu's popularity checker, Google Trends and Adwords, and the Chinese version of the Yahoo / Overture DTC it's still slim pickin's out there on that front as far as I can tell.
Wo bu hui jiang jon wen.