There's tons of such games, and especially when I was a kid (20 or so years ago) and had holidays, we had all the time to play games. Made the time fly so quickly, but of course there's been cases even this year (not as long periods of time at once though) although I barely have time to do anything anymore
So here's a short list of games that I at least remember now (in no specific order):
Master of Orion II (PC)
Ultima VII: BG/SI (PC)
Jagged Alliance/JA2 (PC)
Faxanadu (NES)
Secret of Mana (SNES)
Might & Magic VI/VII/VIII (PC)
Baldur's Gate/BGII (PC)
Icewind Dale (PC)
Fallout II (PC)
Xenoblade Chronicles (Wii)
Paper Mario/PM:TTYD (N64/GC)
Lemmings II (SNES)
Sim City (SNES)
Resident Evil: Revelations (Wii U)
Batman: AC (Wii U)
Assassin's Creed IV (Wii U)
Mass Effect 3 (Wii U)
Lego City Underground (Wii U)
Fire Emblem: PoR/FE:RD (GC/Wii)
Diablo II (PC)
And probably tons more. The biggest single time course during playing these games has been around 6-9 hours, in biggest cases way over 12 hours.