What games have you bought over-and-over again (multiple times)?

The Secret of Monkey Island + SE (5x)
Monkey Island 2 (3x)
Full Throttle (4x)
GTA 3 (4x)
GTA: Vice City (4x)
GTA : San Andreas (4x)
GTA IV + Episodes (3x)
GTA V (2x)
and many other double copies (hard copies + digital)

Neverwinter Nights
Fight the Dragon (to give away to others)
several of the Infinity engine games

Had to think on these...

Star Wars The Force Unleashed
Mafia II
The Godfather
Sniper Elite (series)
Bothers in Arms (series)

Too many to keep up with, even have multiple OS still sealed.

Diablo 1 many times, Hellfire Expansion once (gifted some)
Diablo 2 + LOD (gifted some)
Red Alert 2 + Yuri's Revenge (gifted some)
Command and Conquer series (own both First Decade + Ultimate Collection)

Pretty much the main bulk of my gog library, which i purchased retail back in the day, especially Arx Fatalis, Baldur's Gate series, Bioshock 1, Dungeon Keeper Gold + 2, Morrowind, Monkey Island 4, Fear 1 + 2, Heroes of might and magic series, Legacy of Kain Defiance, Abe's Exoddus, the Suffering 1 + 2, the Witcher 2, THIEF Gold and Deadly Shadows, Titan Quest, Vampire the Masquerade redemption + bloodlines, warcraft 2 and others.

I sold all my discs around 2011 or so, and have bought a ton of games digitally to replace them. Almost any game made before 2011 I've bought twice, then.

I also occasionally re-buy a game I have on Steam from GOG, if it's cheap enough (under $5 or so).

I can't think of many remasters I've bought. The Lucasarts games, Outcast... drawing a blank on much else.

Dragon Age Origins (5x)
Baldur's Gate (3x)
Baldur's Gate 2 (3x)
KotOR (4x)
KotOR 2 (3x)
Hollow Knight (4x)

I think the only one is System Shock, and I only broke down and bought a digital copy after the newer (source-code-based) Enhanced Edition had been out for a while...and mainly just so I could have older versions archived, in case the devs of the ported version keep messing with it for years on end like they have with SS2 and the first couple Thief games. Still haven't played it, either.

Edit before posting: Scratch that, I literally just bought Unreal Tournament on a whim several minutes ago. That only half-counts, though, as the other version I bought years ago was for the Dreamcast, and I don't think it had all the same content of the PC version(s?).

Far Cry 2. This was my go-to shooter for potato laptops for a few years. Very solid, no-nonsense game but lacks variety. Most of the innovations it tried in the single-player fall flat but it has some nice fire physics, which most games just don't bother with. Had it on 360, retail and now on GOG.

Wing Commander 2
Wing Commander 2 Deluxe Edition: (Included 2 expansions). Promptly returned because I couldn't coax it to work under Windows 95.
Kilrathi Saga (Includes Wing Commander 2)
Wing Commander 1+2. GOG

Then there are another 9 examples that were twice. In all cases, the first of which were purchased at least 20 years earlier. About half of the subsequent purchases came from bundles, the rest I found it more convenient to buy at 75%-90% off than to worry about tracking down patches from unofficial sources and dealing with installers that no longer work in 65 bit.

Most game i bought twice but thinking the game i´ve bought more is:

Runaway (10x) and one more digital, XD. I have a serious problem with this game.... but has an explanation:

Runaway versions: big box, 3 cd´s, 4 cd´s, dvd, budget box, gifted with the 2nd (4x), trilogy box, digital. Used and sealed. LOL

Still one of my favorite games -- just something about the atmosphere, traversal, and mechanics. Certainly not the greatest shooter or best story, but a sense of place that I've rarely felt again in a game...

... although this is the point where I'll shamelessly plug Sniper Ghost Warrior 3. Another imperfect game -- clearly moldelled on Far Cry 2 -- with IMHO a great sense of atmosphere and place.

And thought of another game I've bought many times...

Dragon's Dogma Dark Arisen

Have yet to buy it on GOG, but that will happen sooner-than-later

Obviousl Ghost of a Tale, Tangledeep and maybe Kynseed tops the list.

I've double dipped most Nintendo titles in some form, but I'm trying to think of a Triple Dip.

The DS line, I suppose.