A Little Word Puzzle

I've always like certain types of puzzles or mental challenges. Not that I'm always particularly good at them. They don't always adapt so well to the Internet with the ability to Google so much information. The last one I tried, I thought went over pretty well, so here is one more.

Again this is not a contest or race, and is pretty much self revealing (you will know if you got the right answer). That in mind just give the one word answer if you think you've got it.

If someone doesn't jump the gun, I will post an explanation of the answer later

Which word in the list below doesn't belong with the others

bring
sing
buy
catch
seek
think