10. Caretaker (Star Trek: Voyager)Caretaker took the approach of having Deep Space Nine appear as a location at the start of the episode with Quark and Morn both making very brief appearances. Of course, one little crossover point which is missed sometimes is the character of Gul Evek who appeared in Voyager, Deep Space Nine and The Next Generation. Caretaker simply wasn't as good as Emissary from Deep Space Nine, and much like The Walking Dead it spent an odd volume of time with the cast on a farm. The two-part episode really dragged in the middle until Harry Kim and B'lanna Torres finally get back on-board Voyager. And frankly, destroying the Maquis vessel just made no sense in that manner at all. The entire episode felt like a missed opportunity. The crossover element of Caretaker was just to get the ball rolling for Voyager. Of course towards the later series you would have two TNG characters appearing on a semi-regular basis to the extent that Reginald Barclay ended up appearing in more episodes of Voyager than he did in TNG. Whilst those could be considered crossovers at the start, by the time Troi appeared for the fourth time it was less a crossover and more a recurring character.