Topic: Games you've played too much

Monster Hunter Tri on Wii. I easily invested 1000 hours, maybe even more actually, and obtained most (if not all) the weapons and armours. I think there were a few armours and weapons I didn't make because I didn't want them...

Monster Hunter 3 Ultimate on the other hand within 4 or 5 months invested 1200 hours, man that game is way too addictive. x_x

Fire Emblem Awakening, Minecraft, Terraria, Guild Wars 2, Ace of Spades. All over 80 hours, but I'm around 300 hours into Guild Wars 2.

Tf2 Mincraft and Pokemon Mystery dungeon explorers of darkness. That game is so damn good.

451:10 Kid Icarus: Uprising it's just so good, played story mode twice and beat every level on intensity nine. also Zelda ocarina of Time 3D/N64 over 200 hours (but mostly just running around and cutting grass) and Monster hunter 3 Ultimate played it over 300 hours...

You cant spend to much time playing a game if you really love it.
As for games i have played alot.
Played both inazuma eleven firestorm and ogre for 100+ hours.
Pokemon probably has a couple games ive played 100+ hours. Probably alot more for 1st, 2nd and 3rd gen games but hard to check how much time ive spent on those since ive played through those multiple times.
Melee and brawl. Not sure how much but heck of alot i assure you >.<
Super mario 64 (ds). Ive defeated it quite a couple times already. Not to mention all the minigames included in the ds version.
Super mario all stars. First game. Loved it

And if MMO's also count(and this is kind of embarassing). But Runescape 120+ days(not hours; Days).

Monster Hunter Tri
Skyrim
Mass Effect 2
Red Dead Redemption
Kingdoms of Amalur: Reckoning

There are more but those first come to mind.

Super Smash Bros. Brawl - about 500 hours
Battlefield 3 - 315 hours

I'm sure I've passed at least 50 hours in all of these(and more than 200 in most):
Pokemon Emerald
the Legend of Zelda Minish Cap
Kid Icarus Uprising
Pokemon Crystal
Megaman Starforce Pegasus
Pokemon Diamond(probably my last pokemon until X and Y)
Megaman Starforce 2 Ninja
Minecraft
Megaman Battle Network 5 Colonel
Pokemon Puzzle League
Kirby 64 the Crystal Shards
Pokemon Stadium
Paper Mario the Thousand Year Door
Super Smash Bros. Meelee
Kirby Air RIde
Pokemon TCG GBC
Kirby Nightmare in Dreamland
Edit:
Forgot to add:
Mario Kart DS

My most played game on my 3DS was Mario Kart 7 with 249+ hours. That took about 11 months of gaming.

Over the weekend, Animal Crossing: New Leaf took over that spot with 255+ hours. That was accomplished in less than 3 months.

Monster Hunter 3U, used to be Tri until last year.
But yeah, even with Pikmin 3, Dream Team, and Earthbound released I can't stop playing Monster Hunter, lol.

Dragon quest 9
Pokémon black 2
Animal Crossing new leaf( have played over 170 hours and played for 9 hours one day)

Ive played Pokemon Blue a million times, I need to quit... but I can't! being an adult is too hard I wanna be 8 again and make up stories about the games.

Pokėmon Pearl, 850+ hours. I used to be obsessed with this game. Competitive battling, breeding and hunting for shinies with the PokéRadar mainly caused that insane amount of playtime. I still think the 4th generation is the best one, especially compared to gen 5.

I must have clocked over 4000 hours in total into Pokemon over my life, probably even more.

Muscle March

Goldeneye on Wii,I spent over 500 hours on it.

Monster Hunter 3 Ultimate, I've played well over 300 hours, nearing 400 soon.

Pokemon and Smash Bros.

Mario Kart 7, Animal Crossing: New Leaf, Mario kart Wii, Pokémon Black, Super Mario Galexy 1 and 2, Donkey Kong County Returns, Mario Kart DS, and Pikmin 3.

The entire Donkey Kong Country series...I've completed each game AT LEAST four times. It's bananas how I go ape for Donkey Kong. Truly bananas.