gooberking: It would be hard to really nail that one down, but lots of stuff on a routine basis. When I bought HL2 I had never heard of Steam. After dealing with that mess over dial up I pretty much swore of PC games for close to 10 years with maybe an exception or two in there somewhere. (think I got Oblivion when it was new.) I did also try to buy Two Worlds at retail only to find out it was convinced the disk I paid for was a copy.
I finally started buying games after finding GOG. I did end up cracking open my steam account after Khadgar42 gifted me the THQ HB for loosing my job about a year+ back. I've gotten to where I will buy something with DRM IF it is crazy cheap (like 5$) and IF I think I will play it immediately, but it is such a wild detractor that I usually roll a "No way" far more often an "OK." Game CO's can forget about me spending any real money on something so questionable. Your product really isn't worth more than 5$ if you are selling it with a time bomb. Origin, Uplay? Automatic "No way."
I did eye Torchlight and Assassins Creed at the stores for quite awhile. But even at 10$ I chose to wait it out. When they turned up DRM-free I insta bought them both. I played torchlight twice, but have zero plans to buy Torchlight 2. Thought about Max Payne 3 when I saw it for like $5 but not with having to have two accounts for it. A game I was interested wasn't even worth 5$ to me because of all of the strings.
I honestly don't know how some people have never had issues with it all. I've had so many issues over the years I'm fairly confident I'm stupid buying anything DRM'ed - even on the cheap.
In the early days it was misplacing my MOO1 manual. Then getting curious as to why Max Payne always took so long to launch and finding out it launches instantly if you strip it clean. Then the HL2 mess and Two Worlds ones from above. Direct 2 Drive taking my Sword of the Stars copy down in their flames of getting soldness. Now with a good three GFWL games that I know aren't scheduled for fixing I've got plenty of stories all with in maybe 10-15 years and most of that time I spent deliberately not buying games.
D2D, GFWL (and now GameSpy as well)... yet three more examples of how dramatically and quickly an industry can change. But no, no... that would never happen to Steam. We will have Steam forever. Thank God for Steam and its eternal Game-Cloud. If it wasn't for their all-knowing power and wisdom, we might actually have to become responsible for the use, care, and storage of our entertainment software. We certainly do not want that.