The Borg are easily the coolest thing to come out of the Next Generation (that site looks under construction, but the URL is too good not to link). I think the Borg appeal to me for the same reason steam punk appeals to me, aesthetically. In fact, if you check out these instructions on how to make a Borg costume you will see they look suspiciously like instructions for making steam punk costumes I have linked in the past.
Of course, I cannot discuss the Borg without talking about he ultimate Borg, Seven of Nine (Jeri Ryan). I am normally not attracted to blonds, but man is she the one. My favorite character from Voyager, obviously, although in truth Voyager was my favorite of the new shows. It only had one annoying character (Neelix) and a bunch of cool ones in addition to the aforementioned cybernetic sexpot.
On that note, if you are into mechanical women I can strongly recommend 1987 B movie Cherry 2000, if only because it is one of those really bad movies that has a bunch of actors who later went on to be huge names and would like to see roles like this disappear into the void (like Buckaroo Banzai across the 8th Dimension). Cherry 2000 features Melanie Griffith and Lawrence Fishburne in horrible roles.
Anyway, another great logo shirt for fans of the Borg. I must say of all the Star Trek Logo shirts I have added to this site, this one is the coolest looking. Of course, one would wonder why the Borg collective needs a symbol. It's not like they are going to be mistaken for anyone else.
All prices are in USD.