Games you play vs. games you finish

I have come to find that I really play a lot less of the "games you finish". I've been playing through Ico and Metal Gear Solid 3 for ages... both are AMAZING games and truly the height of their craft, but I just don't have too many days where I have 2 or 3 hours straight to devote to a game like that.
The games that I end up playing more are fighting games, shoot em ups, and FPS shooters when there are more people around... generally more arcade style games... I can pick them up and play, sweet!
When I do have the time to actually play through a long game though, I get sucked right in...
Not exactly sure of my point here... but I feel guilty for not making it through so many of these cool, but long games... the "to be played" stack is growing.

