Bing came out with a nice keyword plugin for excel.

[littleman]

http://advertise.bingads.microsoft.com/en-us/bing-ads-intelligence

It requires that you have a Bing ads account, but you don't need to have any campaigns live.  Honestly, it is a nice, high quality tool that brings keywords directly into excel.  Much better than the new shit tool Google would have us use.