Steam is pretty good, but sometimes I am still old school and I will go to the brick and mortar stores. It probably helps them that I happen to live about a block away from a big one, so that might factor into my decision making. Aside from that, if I am really looking for a deal I will do a more general search and see what I can find, but that about covers it.
Origin is a great gaming system to use why newer and better by 5 times then steam you should try it.I have been buying games on Steam for many occasions. I have never tried Origin, though. Steam is good, there's trading here--so you can trade games with someone you meet on the internet.