Usually I find whatever web framework the language supports. This usually tells you a lot about the language, like if it can hide some of the ugly details behind powerful features or if you get to see it all (nothing wrong with the Go approach of 0 magic), basically everyone can open a browser and see immediate feedback. I also like to see how responsive it is and all that.

It also lets you evaluate any database drivers, which are one of the top 10 things I want out of any language I use.