Banjo-Kazooie: Nuts and Bolts - played around 5hrs of this and just couldn't get into it. The N64 games are two of my favourite platformers of all time, but the vehicle-focused gameplay of N&B didn't do anything for me.
Halo: Reach - maybe it's because I played a lot of Halo 3 but I just couldn't get past the 2nd level of the campaign due to boredom. I still plan on playing through it with a few mates one of these days.
Medieval II: Total War - I'm not a big strategy fan but I gave this the benefit of the doubt; after a few hours of play I was too bored to continue.
The problem I have are the summer and Christmas sales where everything is dirt cheap, so even if I only have a mild interest in a game I'll buy just because it's not costing me much. The end result is usually said game going either uninstalled or collecting dust in my drawer.
I should really play Cards Against Humanity; I'm a terrible person.
Thanks for the feedback, I did actually think about inserting images into this but completely forgot by the time I came to post it. And yeah I don't know what it is but every time I see a Steam sale or cheap games on Amazon I just have to get my fix; I have nearly 300 games on Steam and not even half of those installed!