My little nephews actually prefer Playmobil over Lego (when given the choice).
Initially, I found myself thinking that if I was their dad, I would have stimulated playing with Legos or other construction-type toys a lot more. However, after a while I realized that they didn't care about the predefinedness (?) of their toys at all. One day, the cowboy was a cowboy, the next day he was a farmer, and yet another day a policeman. You get the point. Their imaginations just got rid of the guided-play :-)
When I was reading the 'DOSBox or DOS Box?' article on Slashdot today (http://ask.slashdot.org/story/11/05/18/2336204/Ask-Slashdot-DOSBox-or-DOS-Box), I started thinking about this again. These days, when I try to play a game that I used to play as a kid (I'm 30 now), I don't find them as exciting as I did anymore. Megaman is just too hard, Choplifter to easy, Super Mario Bros too ugly, etc. I guess I don't have the same imagination and determination anymore. I often actually need more realism to get as emerged in the game as I did when I was younger.
I think games have grown up, just like we did. Current games are suited for the minds of 'older' gamers.
Nonetheless, when I play a game like Minecraft, everything changes. I'm the same 7 year old boy again, playing with Legos, having a blast. Which reminds me, I still have a mountain cabin to finish...
(By the way, my first post on this forum. Yay!)