Decision: Star Trek or Alien?

I saw these two t-shirts. I love them both but am torn between which one to get! 

Both appeal to the geek in me. One is in my size, Small and the other is Large. Needed help to decide and sent help request via Facebook... 
Friends and relatives chipped in with the decision-making. Now I know who are Star Trek fans and who are Alien fans lol. 
In the end, I went with Star Trek because it probably won't freak people out and it is in my size lol. :D