Steam is great.
The only downside some may have is that once you buy a game, thats it. Its yours forever. No trade ins, exchanges etc.
However, they are often cheaper buying digital too.
And Steam has sales through the year, 2-3 major ones. Where everything is much cheaper. And the they always have something daily through the year.
I usually buy during the major sales. Buy a bunch of stuff and then play those until the next big sale. Unless something big comes out I really want.
I would highly recommend when building your new rig, you get at least a 1TB HD that you can dedicate to Steam only.
That would be in addition to the typical recommendation of SSD for OS/Apps and spinner for User DATA.
The reason is, after awhile Steam games really start eating up space. First big sale comes along, you'll see what I mean
Plus, its nice to have a HD for just Steam to live. Eventually you can do what I did and add a second smaller SSD for Steam as well, and move just the most played or high disk use games to it, leaving the majority on the spinner.