Hi Alec, Gman,
Xenuhubbard has it about right - a mature sensible course of action for somebody considering a tattoo.
Another way is to travel to San Francisco, put on a sailor suit, sink 2 bottles of Wild Turkey, and wander the dock area. Of course, when you wake up it might not just be your shoulder that's sore!
Seriously... ANY tattoo you choose would reflect your present state of mind, what you like and admire NOW. That may well not be your state of mind in 10... 20... 30 years time. Also, fashions change. What's really cool now is guaranteed to look really tacky in 10 or 20 years, just as you're needing to impress your maturity and "well-adjustedness" on others. Bear in mind that while 16-22 year olds are spending a fortune on tattoos, the 30+ are spending a fortune on tatoo removal!
Think VERY hard. Remember that most people will make sweeping assumptions about you based on the presence, placement and design of any tattoo you choose (for example I knew a guy who had a saltire and the words "made in Scotland" tattoo'd into the hairline he had at 18 - which subsequently receded. On seeing this, I along with most people made the assumption that he was a f'ing idiot & won't waste time actually getting to know the guy who turned out to be a diamond).
Don't get me wrong, I quite like tattoos, I just wouldn't have any on me.
Mike.