I have a scorpion crawling down my right shoulder, and an astronomical sign for Scorpio on my left arm. I wanted them in spots I could cover if I ever regretted them and wanted to hide them. It's been 11 years now, no regrets yet.
If I get any more, I might get a gaming related one on the inside of one of my arms. I'm thinking of using a classic cheat code, like the code for Mortal Kombat on the Mega Drive - Down, Up, left, Left, A, Right, Down (DULLARD), or the level select in Sonic (U, D, L, R, A+Start).