9. Star Trek: The Next Generation & Doctor Who
One of the most outrageous comic book crossovers in recent memory, last year's Assimilation volume saw the Eleventh Doctor along with his buddies Amy Pond and Rory Williams coming across the crew of the USS Enterprise-D, and having to team up to prevent an alliance between the Borg and the Cybermen. Yes, that's right, Captain Picard and Dr. Who teaming up; it's the wet dream of many a nerd, one which became a reality in this extremely entertaining comic venture. Yes, it's likely to never actually happen given that Matt Smith's tenure as Dr. Who is soon to be up, and Patrick Stewart is being kept plenty busy with his X-Men duties, but jeez, what geek worth their salt would be able to resist this one if it ever hit the big screen?