Several.

I'm not a hardcore gamer, and I prefer good story and a flowing game, than brutal difficulty or getting achievements and things. I also have MANY other things I enjoy than playing games, so if a game puts me off at some point, I am unlikely to go back to it.

Of the GTA series, I've only ever finished Lost and Damned. Really- I get hung up on some stupid mission and I'm just not going to replay something a dozen times to move the story on. RDR got dropped for the same reason. I'm all for some difficulty, but after rolling a cart over for the umpteenth time in some stupid race- no story on earth is worth that frustration. There is a million other things to do than play a game I'm not enjoying.

That may seem fickle but I'm almost 40 and like the outdoors more than staring at my tv. So for me, games either grab me and I love em, or they don't and I drop em. I mostly play sports games that I sink time and effort into, and there is really no 'finishing' those beyond careers and such. I normally skip a year between sports games. So I'll play NHL 10 last year and this year, then get NHL 12, while I had Madden 09 and just bought 11.

I will say that Mass Effect and Fallout are games that I have finished multiple times each, and those require a huge amount of time to complete.

If a middle age guy can be a 'fan boy' of anything then it's Total War on the PC, where I have many unfinished campaigns (started another, got bored with the faction, etc) and have only touched on Napoleon so far.

I think of games as becoming interactive movies. Mass Effect really comes close in my opinion. And Alan Wake is really movie-like

The horror genre is really good for a game, since the point is personal danger, and that is done in a game where your toon can die. You project YOU into the character, and his danger is yours.

Most horror films lose people because they have no control of the situation, and so it breaks that illusion. But when you ARE the person in danger....it connects.

Games can also do much more with environment, as you can take time to explore it and make it detailed (and creepy).

Very few horror films are worth watching these days (maybe I just got old) so a horror game offers a real chance for suspense and moments of panic than any movie. The sheer gore that games can have (alot cheaper than FX in a movie) makes them prime for horror genres.

Sadly, several horror games I've played haven't been good. I really disliked Dead Space- it was repetitive, drab, not actually scary, and the controls blew. Condemned was creepy but slow and overly difficult. The Darkness was solid, but pretty much a standard shooter.