There are so many tattoos I'd love to get, but I'm too much of a chicken shit to ever actually do it.
My best friend passed away a few months ago (on my birthday, exactly a month after his, no less), so I've been toying of the idea of getting something for him next March. I can't decide between a musketeer sword (him, myself, and our other two best friends were nicknamed the Musketeers) or the Musketeer cross, wrapped with a ribbon. I'd probably have it done on my right arm, since that's what he was to me.
The other one I'm thinking about would be the chains from the main character in BioShock on my wrists. When I graduated high school, my mom gave me a copy of Ayn Rand's "Atlas Shrugged". It changed my life, and gave me a purpose and direction, and profoundly shaped my beliefs. I've always been a big gamer, and I like to think of it as a way to unite the two. The chains are a reminder that, as Andrew Ryan says, "A man chooses, a slave obeys.". One of the basic premises of Atlas Shrugged is that one man was capable of bringing the world to a halt, simply by choosing not to obey.
The last one I'd want done would be an Autobot symbol on my left shoulder. Growing up, my dad was... distant. Odd and strange as it sounds, I always looked to Optimus Prime as an example of who to be. It's a connection to my childhood, and a reminder of the man I want to be.
However, I'll probably never get any of these.