For me (to have a pin in my home) - it is ultimately the FUN factor. I am often surprised at which Pins I find Fun and which ones I don't. My personal examples below.

example 1: Scared Stiff. I fell in love with that game at a fellow collectors home and just had to have one. I had no desire to own that theme but after playing it I just felt that the overall package, sounds, lights, theme, gameplay and innuendo just made me smile and have fun every time I played it. I only sold it because I needed to fund my Tron LE - it is the only game that I really miss (owned it for 3 years).

example 2: TSPP. I love the show and given the great theme integration and awesome toys - I should have loved that game. I don't like it and I have tried so hard to like it (tried to force myself - played it tons!). It has everything that I should like but it just doesn't give me Fun.

example 3: Lord of the Rings. An absolutely awesome game to play but it can be a lengthy adventure. I don't play it much but it is perhaps my favourite game - I just don't have that much time to play it but when I do - man that games is kick-ass Fun.

example 4: WOZ. I love the gameplay and it's uniqueness. This is the only theme that I hate - because I absolutely cannot stand the movie (not sure why - I think it is because I hate the Lion character). Only theme I don't think I could own but I really want to own it to play for a bit - almost convinced to buy (for a while). It is a great game to play and I have Fun playing it.

Theme is important to me (to own - not to play) but it is the overall package - I am a lights/sound guy (love home theatre setups) - audio completes the experience for me.

I really have to play a game for a bit to determine if it is worth (me) owning. While I quite enjoy hearing what others think - I never blindly follow the crowd. I like what I like and enjoy playing games I don't think I will like because you never know.