[Nintendo] Games only get boring if you play them to death. Yes, I do play a game for hours at a time, but I take breaks in between, that way you cool down, in a sense. Or when you complete the game, give it a few weeks before you begin playing it again. When you play a game, your excitement gradually goes down and you're like "I'm tired of this" before you know it. It's sometimes a good idea to stop long before you get tired, that way the excitement can easily replenish and it feels fresh when you start up again. I found this out with PM and PMTTYD. I played through PMTTYD almost constantly then-- probably six or eight times in past 3 1/2 years. I don't play it much now, as I played the heck out of it and it doesn't feel as fresh-- I will give it time before I want to play again. However, with PM, I have played through it completely only 3 times (finished it today) in the past 7 years, and every time it felt completely fresh and awesome.
Probably the only game that for some reason has incredible lastibility for me is Luigi's Mansion. In the past 7 years (mostly in the first three) I played through it at least 50 times (counting when I didn't have a GCN Memory Card).