Tell me single p. games on PC, PS 2, Wii or on any consoles what have a lot of hours on it! (+GA)

Borderlands 2 :3

PS2:
Rockband 2
Shadow the Collossus
Metal Gear Solid 3: Snake Eater
Star Wars Battlefront 2

PS2 : Persona (3-4, Golden for Vita)
Wii : Muramasa Demon Blade (Rebirth if you have vita)

I have +200 hours in Mario Kart for the Wii, so you might want to try it out.

Fallout 3, any bioware games, i recomend the new ones obiously but also try kotor 1 and 2 and jade empire, any bethesda's games ofcourse

Divinity Original Sin!

Hogs of War for the PS1 (certainly playable on a PS2).

No, it doesn't have a huge world to explore, but it has a lot of different levels and does have some explorable content to a certain extent; It'll bring you hours of fun; Probably one of my most played games on the original PlayStation if not ever.

Counter-Strike 2,067.9h ^_^

Kingdom Hearts 1 and 2 for PS2 Any FF game, Incredible hulk ultimate destruction for PS2, SpiderMan 2 for PS2, Prototype for PC. Reply if you have beat Sephiroth in Critical mode in KH 2.5

Paper Mario: The Thousand-Year Door, for Game Cube(compatible with Wii), mega awesome game, there is also another for Wii, but it's not good. It's a has big explorable world, is open world, RPG, tons of secret stuff, awesome boss fights, cool places.

Or Star Fox Adventures for Game Cube(compatible with Wii), my FAVORITE game on that console, it's just ultra awesome. Again RPG, open world, lots of stuff to do, space battles, dinosaurs, cool planet with beautiful places, Fox himself and his squad.

I'm playing PlayStation games on my phone, already finished Crash Bandicoot, Final Fantasy VII and I'm currently plating FFVIII.

you can get Okami for PS2 or Wii. it's a great game, but vastly overlooked. should do you good for about 40 hours if you want to complete it all :)

if not, they have been mentioned before but the Kingdom Heart games are really good, long and full of exploration aswell :)

GTA, especially San Andreas
And try eidos game (Deus Ex, Hitman, Tomb Rider, Thief)

If you like hack and slash, maybe Dynasty Warriors (Available in PC and PS2, not sure for Wii)

PS2

Metal Gear Solid 2/3

Final Fantasy X

Ratchet and Clank (any of them, they're all good)

Shadow of the Colossus

Haunting Ground (an overlooked survival horror game)

Mercenaries

PC

Valkyria Chronicles

Fallout 3 / New Vegas

Terraria (really addictive)

Deus Ex: Human Revolution

Dead Island

Final Fantasy VII

Civilization 5

XCOM Enemy Unknown

I could go on but I'll stop there.

gta
watch dogs
mass effect
dragon age
fallout
elder scrolls

well, stop playing dota 2 since 5 month ago, i star playing open world game like GTA and saintrow..

Rise Of Nations :) Pokemon also

Dynasty Warriors 8

Mass Effect trilogy, even if you don't like science fiction or space stuff, just give it a try

I spent an astounding amount of time on Rune Factory 4.

Begin with Fallout 1/2 & Planescape: Torment.
You will have one of the best single-player experience ever.

And try Civilization V Complete (not new Beyond Earth title!) to dive into ocean of possibilities.
You can start here: http://www.civfanatics.com/

So it's pointless for me to recommend Redguard? ;)

Anyway here goes:
Arcanum
Planescape: Torment
Baldur's Gate
Temple of elemental evil
Dark Sun: Shattered Land
Ultima 7
Ultima 7 part 2
Ultima Underworld 1-2
Ultima 5
Lands of Lore 1-2 (possibly 3, I've not played it yet so I can't comment on it)
X3: Terran Conflict
Tachyon: The Fringe
Privateer
Sea Dogs
Might & Magic 3, 4-5, 7 & 8 (you'll get why I wrote it like that when you play the series)
Divine Divinity

Xenoblade, For the Wii. I alerady reached de 100+ hour mark and haven't even finished the game yet. Its a huge RPG with an excellent story and soundtrack! The game is gorgeous, considering the console and that its an 2010-ish game.

Monster Hunter (first episodes on PS2, a couple on PSP, one on Wii but online is now closed, the last on WiiU/3DS, next one on 3DS) series can take away a good chunk of your spare time, the world isn't really big but the monsters and weapons to fight them with are a lot.
Otherwise there is Xenoblade Chronicles for Wii (or pc with Dolphin Emulator, maybe even better and easier to get), and Tales of Symphonia Dawn of the New World is quite long and good. Good old Smash Bros Brawl can last long if you want to unlock most of the stuff and play with your friends.

You can also look at Fallout New Vegas on PC.