Here's mine, I actually have a top 3.
The first and most important on is the
Castlevania 20th Anniversary pack, which came as a pre-order bonus with Castlevania: Portrait of Ruin. Actually, this is so important that when I realized I had misplaced the CD from it, I tore the entire house apart looking for it. Finally found it last night, in a generic plastic case mixed in with PC stuff for some reason.
Next I have my Hallmark Arcade Ornaments. Pac-Man and Galaga, these things are sweet, it just sucks that Hallmark didn't release another one last year. There was a huge uproar about it, perhaps they'll produce another one soon.
And finally, the Dragon Quest Slime Controller for PS2. This thing is so awesome, I've never used it though. I just like the fact that I have a giant DQ Slime in my living room. haha