I'd agree with LOTR... but I think to truly enjoy it, you have to be a fan of the LOTR theme. Doesn't get any deeper... we've had ours for 3 months and we're still haven't figured all of the rules yet. Only issue I see is that some small kids can get scared by it (sh*t, with the 12" sub, I still get scared when ballrog roars...). Also, you've really got to be in the mood to play LOTR... it's emotionally draining and you have to be prepared for the epic voyage.
Spiderman is also a great option... pretty universal theme that adults and kids can enjoy... it is by the far the pin that gets the most play and the last one that will leave my collectionn.