I was a bit passive with the original post - I was the one who came up with the idea of getting a tattoo, and we've worked through a number of ideas, before the wife suggested an alien, and I thought it would be awesome.I think you should do what YOU want... Don't worry about family and coworkers (especially them) and whatever they keep saying to you.
If you can close your eyes and see yourself with a tat, then go for it. Gathering ideas is half the fun
However if you flip flip too much on the idea I suggest you not get it at all.
It would be my very first, but I'm surrounded by enablers, lol.