I'd have to say LOTR. I've had mine for almost 5 years and its still fun to play. I've played the other games on your list and they are certainly fun in their own ways, but I just find LOTR to be a bit more engaging to me. I'd sum it up this way, LOTR has a nice balance of flow, depth, and features - SM similar in this assessment - Tron is fast and unforgiving with a cool audio package - ST - smooth flow and a cool light show. So I like balance, and though LOTR can serve you up some long game times (I'm fine with that, just means I'm playing one game instead of 6), the theme appeals to me more than SM.