The random mazes in KQV were what got me to quit the game, actually... I've never gotten past the desert. :)
... Hmm, I wonder why I'm not sure if I want to bother with these... :D
I did get through KQVII's desert, but that was much farther into the game, simple, and I used an FAQ. I did eventually finish that game... the only one of the three KQ games I've played much of that I finished (yeah, I own KQs 1-7 now... but I've only actually played 1, 5, and 7. Never got around to even trying 2-6 yet...). Both back when we first got the game and in every of my several attempts to play it again since, I just haven't gotten up the interest to FAQ my way through KQV.
I have plenty of other adventure games I've owned for years but either haven't finished, barely started, or haven't even started, too... for instance...
The Longest Journey (got maybe 2/3rds of the way)
Dreamweb (didn't start)
The Crystal Key (I've owned this for like 12+ years, but never started it...)
The Last Express -- Fantastic style, but having to learn where to be at each precise point quickly started being more frustrating than fun... very interesting concept, but I didn't really enjoy the execution, in the end.
KQ 2-6 -- Never started these
Space Quest 5 (almost finished, but got stuck on a near-impossible timing puzzle near the end)
Quest for Glory 4 (um... no excuse here. It's one of the best games ever. I have gotten pretty far, at least, near the end.)
Quest for Glory 2 VGA Remake (why haven't I even started this, after waiting for it for so many years??)
Inca II (barely started)
Timelapse: Ancient Civilizations (got stuck at the sliding tile puzzle about 3/4ths of the way through the game. Eventually gave up in extreme frustration.)
Myst (quit at the beginning, bored)
Maniac Mansion (barely started)
Maniac Mansion: Day of the Tentacle (I've always liked other Lucasarts games more... I play a bit, think 'this is good', then think 'but Fate of Atlantis/The Dig/Sam & Max/etc. is better, I should get those instead', then stop playing. Hmm.)
Indiana Jones and the Fate of Atlantis (absolutely loved it, but it was too hard for me to finish when we first got it (though I did get at least half way through), and then I lost the CD five or six years ago so I can't go back and try it again...)
Dreamfall: The Longest Journey -- Just waiting to get another gamepad before I continue this one, it's no fun with keyboard. It's easy but good, with a great story.
Laura Bow II -- Sierra random deaths and frustration stops being fun quickly.
Chronomaster -- never played.
The Journeyman Project Turbo -- never played.
ToonStruck -- got a bit in, stopped for no reason. Seemed good.
RedJack: Revenge of the Brethren - Same as above.
Hugo 3: Jungle of Doom! -- Somehow this seemed harder than the first two Hugos...
Touch Detective (on DS) -- not too long, entertaining and funny, and pretty easy too... why haven't I finished this up yet, I got like 2/3rds of the way...
EcoQuest: The Search for Cetus -- we had this when we were younger, and back then I remember getting ALMOST to the end, like right to the last puzzle or near it, but getting stuck there, never finishing it, and later losing our save files... bah!
Lighthouse - never started
Freddy Pharkas: Frontier Pharmacist -- started, but stopped midway for no reason. Seems like a pretty good, funny game. :)
Douglas Adams' Starship Titanic - haven't started yet (I want to play it, though!)
I won't count ones I played some of but don't currently have (okay, I listed Indy, but no others), like The Dig (I want it! Awesome!) and stuff.
... Erm, I have a pretty bad track record with this genre, don't I...
I also won't list any of the text adventures I have, because aside from Zork 1 (I have 2 and 3 too, but never started them), I've never really even considered playing them. Well, I did consider playing Planetfall a few times because I've heard it's pretty good and I do own it (with the map, too), but haven't. I also won't list games we own but I never even considered playing, like Riven or Titanic: Adventure Out of Time.
Survival Horror Games -- I have a bunch, but no, I've never finished one... unless you count Eternal Darkness, which I beat (twice, almost) but I really can't count that as either an adventure game or a survival horror game, despite definite adventure and survival horror elements. The core of the game is more action-adventure. But anyway... the games.
Resident Evil 2 (N64) - got partway
Resident Evil 0 (GC) - got partway
Resident Evil: Code Veronica (DC) - never started
Carrier (DC) - barely started
Blue Stinger (DC) - got a little way in, but not that far... I've always kind of liked the game, though.
The Ring: Terror's Realm (DC) - barely started
Dino Crisis (PSX) - started, but didn't get far
Silent Hill (PSX) - never started
There's also Koudelka (PSX), a survival horror RPG, which doesn't count either but I'll mention anyway. I've nearly finished the first disc... of four... in a game where each disc is only a few hours long. :) I also have Fear Effect (PSX) (I'm somewhere on disc 1 of 4 there too), but that's more stealth action.
... are there any I HAVE finished? Um... a few, anyway... not all that many though.
Quest for Glory 1 (several times, I think)
Quest for Glory 3
King's Quest 7
Grim Fandango
The Secret of Monkey Island
The Curse of Monkey Island
Escape from Monkey Island
Hugo's House of Horrors (the first graphical adventure game I ever played, as far as I know... I still enjoy this simple little game. :))
Hugo 2: Whodunnit?
Zork Grand Inquisitor
Zork 1 (maybe... I know I played it, and I might have finished.)
... And can I just say I finished Space Quest 5, because I got almost to the end and only stopped because of a technical issue, not because I wanted to?