A Game with the Most Replay Value

[Voxgizer]

Team Fortress 2. I've clocked nearly 600 hours, and know people with well over 1000.
Dungeon Fighter Online. I've probably clocked more than TF2 alone...

For the realm of single player most of the Street Fighter series, Castlevania, MegaMan (up to X3). I mostly enjoy the older, more simplistic games.

 

[Erebohr]

Shadow of the Colossus. The epic battle music is reason enough to replay it.

 

[Super Toast]

Bully, TimeSplitters: Future Perfect and Team Fortress 2. I've spent an ungodly amount of time on each of those games. (Read: 350+ hours each)

 

[Saargston]

I beat Super Mario World more times than I can count.

 

[Faux Furry]

JRPG: Chrono Trigger and Chrono Cross have new game plus, multiple endings and unlockable content waiting to be uncovered across repeated play-throughs.

Hack-and-Slash: Bayonetta was already mentioned, but the Devil May Cry series has similar motivation for repeated replays, fitting as both Devil May Cry and Bayonetta were cooked up by teams with Hideki Kamiya at the helm.

Fighting Game: It's a toss-up between Soul Calibur and Mortal Kombat(2011). Not only will the fighting systems take a good long while to master, there are lots of characters to play and even more extras to unlock.

Adventure Game: Heavy Rain. It has as many branches as a kudzu and unlockable rewards for seeing every one of them.

 

[Andy03]

666 in TF2 right now.

I'm not sure if I want to play it right now...

 

[kakaomasse]

Minesweeper, the ultimate trial-and-error game.

 

[Shreder55]

Saints Row 2 and endless possibility's of what you could do (or blow up)

Fallout 3 or New Vegas the world is huge so there lots to see and do.

and Tales of Symphonia as I have sinked 200 plus hours into playing it. It is the largest RPG I have ever played and I have beaten it over 5 times.

 

[Best of the 3]

Played HL2 through about 7 times. I am pretty good at that now and can tell exactly when an enemy will strike and from where. Elder Scrolls Oblivion is another game I have played a lot. Still not 100% on it though.

 

[infohippie]

Oblivion, because you can just spend so long roaming Cyrodiil investigating dungeons that you chance upon.
Portal, because I always start that up when I can't think of anything else to play and I've got an hour or two spare.

 

[malestrithe]

Tekken 6 would be it.

 

[DEAD34345]

Likely some sort of simulation game. In this case Dwarf Fortress.

This. The replay value is infinite because the game never ceases to surprise you with new and violent ways to for your fortress to end.

Then again pretty much any roguelike has tons of replay value, it's one of the key features of games in that genre. Nethack, Liberal Crime Squad and Dungeon Crawl: Stone Soup are probably the ones I have spent the most time on (other than Dwarf Fortress).

 

[Stako]

Diablo 2 and Symphony of the Night. I really can't think of any other for now...

 

[Prof. Monkeypox]

Pokemon and Team Fortress 2.

Only games I ever sunk 100+ hours into.

 

[Assonabum]

Oblivion. That game consumed a good 300 hours+ of my life

 

[sinkirby]

Pokemon, Diablo two, Rome ...or any Total War series games... Fallout 3, Sims, Silent Hill, Resident Evil 4 etc etc

 

[Josh Horton]

TES IV: Oblivion
Ninja Gaiden Black
Bioshock
FF Tactics
KotOR
Fallout 3
Borderlands
The Dishwasher: VS
Portal

Those are a good majority of all the ones I've played through 5+ times. On all difficulties of course

EDIT: How the hell did I forget Portal??

 

[BehattedWanderer]

Just played Chrono Trigger. I'll be playing that again until I get better at it, knowing all the grind spots, learn all the best combos, and get all the endings. Or most of them, anyway.

Also, having just played the English version of Mother 1, I'll play it again soon so that I can learn that as well as I know Mother 2/Earthbound and Mother 3.

Oh, and that part of the Co-op portion of Portal 2, the one that requires no deaths. Since I intend to do that, me and my friend are gonna have to learn it inside and out.

As for games I've already played many many times...Paper Mario, Paper Mario: TTYD, Earthbound, Dragon Age: Origins, Ocarina of Time, Twilight Princess, New Super Mario Bros Wii, Gauntlet: Dark Legacy, and Baldur's Gate: Dark Alliance 1/2. And Just Cause 2, if that counts, since there's only so much to do, and as soon as you learn it you'll know it anytime you play. 89% and counting...

 

[Joos]

Kotor was good for one replay; two in total.
Vampire the Masquerade: Bloodlines. It was good for three or four playtroughs, just to experience the odd vampire backgrounds and explore all the multiple endings.
Mass Effect 1 & 2: Paragon and Renegade
Diablo 2: I played through with Barbarian, Paladin, Necromancer and Sorceress. The other classes weren't really all that appealing.
I've decided to give Dragon Age: Origins a second go sometime soon.

 

[EGtodd09]

I played Mass Effect 2 6 times or so, once for each class. It's a 30+ hour campaign so that's about 180+ hours of gameplay. I did the same with Fallout 3, but for 200+ hours at least. Just Cause 2 kind of, but really that was just 173 hours of awesomeness and I only played through twice. Pretty much any single player game with classes or heavy sandboxing (Crysis 1 is heavy sandboxing, Crysis 2 is like medium sandboxing and STFU I know it isn't a word). Actual sandbox games don't actually have replay value though, because you just play through once or twice and spend most of the time messing about.