Ever had a game that you could just play over and over? It could be a decade old and you still play it like the day you bought it. Pretty sad that , although I have played Halo hundreds of times, I seen to usually forget my strategy 
āI wish I knew how to quit you!ā
Castlevania:Symphony of the Night. I have had for nearly a decade (since '97) and I still play it over and over again without getting bored, even though I know the labyrinthine castle like the back of my hand.
Final Fantasy!!! VII, IX and X!!! But mostly VII
Mitsuko, there are some games that I would like to play more than once and yet I donāt somehow. Call me a lazy bum, but no matter how good the game is I just donāt have enough patience to go trough the same mazes and same battles all over again no matter how amazing the storyline is.
There is one game though that I play quiet often. Itās not a RPG, not an action game, not a shooter or a racing game. Itās a strategy game. How about ā¦ Chessmaster? I play this brainteaser for at least 10 years, with regular upgrades of course. Iād rather play the machine than a human opponent, this way I donāt feel as bad when I loose. 
SaGa Frontier. But not because I particularly like the game, although I do. I play it because it indulges my obsessive-compulsive nature easily. Itās a warning sign for me, actually - if I feel like playing SaGa Frontier, then I am depressed and need to be careful. To date, Iāve logged undreds of hours in this game, and I STILL havenāt beaten it, whether itās from lsot interest, or memory card wipes. And anyway, with the ālevellingā system in it, itās easy for me to fall into a rut, which I enjoy. You know where you are, when youāre in a rut.
Legend of Mana. Between the cute animation and music, I canāt get enough.
Zelda: A Link To The Past. After all these years, when I feel like it, I can devote a day and beat it. I confess to like just walking around, from time to time.
Second candidates would be Starcraft, which finally suffered from the āyouāve beat it a dozen timesā syndrome a couple of years ago and Warcraft II, which is still nowadays replayable (but the first campaign of each side is a drag and I donāt keep saves).
Almost forgot: Tetris. Tetris is my nighmare and Iāve resigned from trying to achieve (and surpass) high scores. That Russian was a genious. And Nintendo for [STRIKE]stealing[/STRIKE] buying it that cheap. The GB version is the best 3v4r.
Nethack.
Coughs.
Yeah.
The Longest Journey.
Civilization II.
Birth of the Federation.
Sonic 3, I mustāve beaten that 20+ times yet each run-through is as enjoyable as the last. Donāt even usually lock-on S&K either, despite the sheer quality of the joined game. Other winners include Cool Spot (vastly underrated classic), James Pond 2 and the first 2 Toejam and Earl games.
Note how these are all Mega Drive/Genesis games? 
The entire 4x empire-building genre. ESPECIALLY the civ games and Alpha Centauri
Iāve played Ocarina of Time, Planescape: Torment, Baldurās Gate II, Chrono Trigger and Final Fantasy Tactics so many times I canāt even remember. Aside from that, I plow through any Megaman X game whenever Iām bored and play some Age of Empires II over LAN with my cousin.
Crystalis, okay I know kinda dumb, but it was my first rpg and I have never over come my love for it.
Demigod, where on earth or the web did you get the cute little devil girl or whatver she is above the words, do you use your powers for good or awesomeness? Sheās so kawaii my eyes want to melt! Er, kawaii is a good thing right? LOL kinda showing my age there.
Letās marry and baby and stuff.
Seriously, I totally agree, that game can be played so many times, over and over with new temperings and stuff. I love it to death and will never get bored.
I may have a 999 damage axe, 99 all in armours, and have otherwise entirely maxed out all item slots, but that doesnāt mean I donāt still love it. I start a new file every summer, pretty much, and beat the game three or four times in it.
I go back and replay a lot of the older 8-bit and 16-bit RPGs over and over again. The Dragon Quests, the Final Fantasies, the Lufias, the Lunars, etc. For other genres, I find myself much more interested in older fighting games than newer ones, and I still play the classic Mega Man games, the classic Zeldas (the first four), Kid Icarus, Bionic Commando, Little Nemoā¦ well, a lot of stuff. I guess thatās why I <A HREF=āhttp://www.rpgclassics.com/staff/mrsaturn/collection/ā>canāt get rid of anything</A>.
Oh, I almost forgot puzzle games and PC simulation games. Tetris, Panel de Pon, and Meteos take up some time fairly often, as do Civilization, SimCity, and various PC RTS/TBS games.
I agree with those that said Legend of mana, too. itās such a beautiful game, and I always find something new to explore. I never get tired of the Jumi Arc, and the others are always fun to explore.
Luca from Black/Matrix Zero. Apparently sheās in a couple of the other Black/Matrix games, too. A friend from the anime club at my college gave me the rom (GBA), but unfortunately thereās not an English release and the patch only has basic battle menus translated. The Sprite in my avvie is from the game, the sig image I found via Google. Iāve got ones for the other characters, too.
I have a short attention span, so no games so far have fit that category 
I hope spore can 
I have several games I can never stop coming back to. Both Fallout games get played at least annually, FFT gets a go pretty often, I go on week-long nethack binges about every 9 months or so, Vanguard Bandits gets brought out on occasion (one of these days Iām gonna finish ruin branch, I just know it). I havenāt had Dai-3-Ji Super Robot Taisen Alpha long enough for it to really count, but Iāll probably be digging it out every few months to further my eventual goal of clearing it with all 4 main characters and getting all the secret units.
And then thereās Starcraft, which my friends and I always end up coming back to for at least a month every semester. Itās about the only way some of us ever hear from each other now that everyone is scattered across various universities.
NES:
Contra
Super C
Rush N Attack
Cabal
Gauntlet 2
Paperboy
Double Dragon 3
Other
Most 2D Fighters I like (SF2, SF3, SFAlpha3, GG Slash, Marvel Vs Street Fighter, Capcom Fighting Evolution)
Final Fight
Resident Evil: Nemesis
SaGa Frontier
Legend of Mana
Dragon Quarter
Also, all the Mega Man games were there at one point until I decided to learn how to beat them all with the minimal amount of powerups (I can beat X1-5, X8, and MMZ1-4 with absolutely nothing), so now I just play them until I achieve that goal, and then they lose their flairā¦cos after all, what can you do after that?