+1 for the Power and Light area. Fun place to hang out in the evenings.
I second 75th St Brewery. I haven't been there for awhile but pretty cool place to go.
There's also a Granite City on the south side in Olathe if you are in that area. There's a Gordon Bierssh as well out at the Legend's by the Kansas Speedway.
You can't come to KC without having BBQ. I'm sure I could start a war on where to go, but my fav is probably Arthur Bryant's. Great place, was just there yesterday.
If you can make it Lawrence KS (about 40 minutes away or less depending on where you are) there is an excellent brew pub called Free State. Great college town, home of University of Kansas so there's plenty of night life there as well. If if you are not able to make it there, you should be able to pick up some of Free State's beer in the bottle shops around town.
Also not sure if you are able to get any of Boulevard's Smoke House series in Benton, but you should try a few of those beers if you haven't all ready.