30 GOG titles fit the bill.

Too many to mention here,but look on the bright side in 1000 years they'll be worth heaps.

Spelunky, La-Mulana, Thief I & II, and System Shock 2 are all games that I adopted multiple times. Sure, the first editions of Spelunky and La-Mulana are free, but the experience they gave me was enough to convince me to buy the commercial versions.

Can't remember how many version of baldur's gate I have.

Let's see,

Far Cry
Painkiller
Shogo (couldn't find my old copy)
UT2k4
Trine (I had it on PS3 then got it here)
Enclave

Star Wars The Force Unleashed

When I first became a PC Gamer, I still had alot of habits and game interest from console. I didn't know much about the PC market, either. All I had to go off of at the time was an article regarding PC Gaming not being dead from the now-defunct Gamepro magazine. I initially bought The Force Unleashed on Steam. After seeing how huge the download was, I bought the retail copy.

Star Wars Battlefront II, X-Wing, TIE Fighter, and Galactic Battlegrounds

I had Galactic Battlegrounds since I was a little kid, and still have that retail copy. The other three, I bought in my early days of PC Gaming. For all of these games, I got the GOG versions.

Rise of Nations

I tried the game out at my uncle's house, shortly before becoming a PC Gamer. I ordered a copy off of Amazon. Last year, I bought the Extended Edition on Steam. I plan on keeping my retail copy, in the event STeam shuts down in the future.

Those are the only ones I can remember.

S.T.A.L.K.E.R. Shadow of Chernobyl

gone through four disc versions (still have the original but its too scratched to make use of), have it on GG and steam and intend to buy on GOG when I can.

Red Faction (PC and PS2), STALKER CoP (Disc and GOG), technically these next two are ones I bought the physical editions of and received the GOG versions of no charge to myself: The Witcher and Mount and Blade, AoE II, Risen (Xbox 360 and GOG), Commandos Beyond the Call of Duty (disc and GOG), Grid (physical and GOG), Star Wars Battle Front (one in Fan Favorites and the other in 3 disc version), and I do believe that finishes that.
Edit: Rise of Nations. One's my original Ron + Thrones and patriots, the other is a little different in that it has a cardboard sleeve and no art on the case itself. I do wonder.
Once more, dear friends, once more: Battlefield 2 normal CD version and the collection with the booster packs and such on a DVD.
Edit: Blitzkrieg II and I have Call of Duty 4 twice on DS and once on Wii.

There's many games in my GOG library that I already had other versions of.

I came to GOG in the first place to get around disc-check DRM's on CD- and DVD-versions of games I own. It's the kind of DRM that annoys me the most, having to swap disks a lot and getting your drive damaged after 1-2 years of running SecuRom and Starforce-ed games.

Examples of those are Baldur's Gate. I got the DVD-versions twice, before I discovered GOG, then there's the Enhanced Editions, making 4 copies of Baldur's Gate I, plus 5 copies of Baldur's Gate II, for I bought the old carton box in a second hand store because of the booklet.

Another example is Heroes of Might and Magic IV (discovered it with a patch before my eye first, than bought the disc version, then bought it on GOG).

With games that aren't available DRM-free, I sometimes have bought a physical back-up copy for if my first copy gets scratched, like Battlefield 1942, Vietnam, Battlefield 2 and Rome Total War, I own all of them twice on disc. Than I discovered Total War gets sold digitally on Gamersgate, making the total 3 copies of RTW.

Then there's the case where I get tempted by sales on Steam or Gamersgate, that tempt me with prices that feel OK for a rental game (as you don't own Steam games, I only buy them if they're dirt cheap or get bundled), but then they're on sale on GOG, and I end up with multiple copies in that way. An example is GRID, which was expensive on GOG at first, but got on sale later on.

And that's just a few of many examples



TL;DR: lots of different reasons why I end up with multiple copies. I named only a few of them, but there must be dozens of games like that in my collection, TMTC (too many to count).

Baldur's Gate, Baldur's Gate II, Icewind Dale, Icewind Dale II, and Planescape: Torment - all on disc and GOG.
Half-Life and its addons - in an old-school cardboard box (Half-Life Anthology or something), then again in a DVD case because I'd lost the discs and the key(s) from the first copy wouldn't register on Steam so I had no way to play them.
Saints Row 2 - for Windows and X-Box 360
Anomaly: Warzone Earth - Humble (Bundle) and GOG
Darwinia - ordered a CD (and a poster) directly from Introversion, then bought it again from GOG
Icewind Dale, - got it in a Humble Bundle and thought it was much too good for that price so I bought it again from GOG, then it was included in one or two other bundles but those don't add more copies, just more money paid for that one copy.
Dust: An Elysian Tale - again, bundle, then GOG because it's that good.
Ground Control - disc, then GOG
Homeworld II - twice on disc from promo bins, second time because I forgot I had it already
The Longest Journey - Swedish-language version (Den Längsta Resan) in an old-school cardboard box, then English-language on GOG.
Myst, Riven, and Myst V - first in DVD-style cases then on GOG, I also already had two disc-only copies of Myst for Mac that were given to me by people who got them bundled with their Mac.
Myst III: Exile - double DVD case (yes, pretty much two DVD cases glued together, I'm still not sure whether I should instead have bought the similarly-sized cardboard box that was also available - the latter looked much better, but I wouldn't have had this story then to tell), and I later found a Collector's Edition box so I just had to buy that one too.
Uru: Ages Beyond Myst - DVD-sized Collector's Edition cardboard box (didn't have any expansions yet), then GOG.

There are most likely many others, but these are ones that I remember after a quick look among my discs and GOG collection.

Oblivion, fallout 3 and NV, terraria (don't get console version, it's awful), borderlands 1.

edit: oh and myst, seventh guest. derp.

I have the Baldur's Gate collection on CDs, and on GOG. I also own the Enhanced Editions of both games.

I bought The Elder Scrolls IV: Oblivion 3 times on Xbox 360, and I later bought the Elder Scrolls Anthology for PC.

I bought Fallout 3 for Xbox 360, then I later bought it again on xbox as GOTY-edition, and I bought it again on PC a while later.

This guy bought 30 copies of Sacrifice.

addendum to my previous post, i did a quick count:

I got 24 games in my Steam library tagged 'Elsewhere with less or no DRM',

I got 9 on Gamersgate that I later got DRM-free on GOG

I got 7 DRM-free on games that I later bought on GOG, as I like GOG more

I got another 24 games on disc that I've got in digital form now (some without, alas some with DRM)

I got 7 games on discs that I have other disc versions of (for fear of them getting scratched)


not 71 different games though, as some games i got more than 2 versions of fit in more than one of the above categories

Plenty of games I've rebought from GOG or elsewhere years after their release, but the worse I've done as a frenetic hoarder was buying in three days three copies of Vampire the masquerade : bloodlines when it got out in 2003. I remember the dude at the store asking me if the game was any good while Half life 2 was selling by hundreds and he couldn't care less about Vampires but were freaking at my hoarding instinct. I've still got those three copies somewhere...

My only regret was that there weren't any fool doing the same at the time. Maybe Troïka wouldn't have shut down...