All missions have merit, but some are just so amazing you wish you could do them for the first time over and over. Now that said, there are some missions that are just jaw-dropping for one reason or another, ones that stop your heart or tear at it. Instead of being faced with the usual desire to just move on ahead once you've 'out-leveled' a zone, you literally scour to make sure you don't leave any task undone lest you miss out on any of the story. Fortunately, you needn't be a completionist to have a drive to seek out and experience every single mission. So missing a mission means you might miss some tantalizing tidbit. All the missions spread throughout the zones, from investigation to sabotage to even the piddliest of little side missions, tie into the story in some fashion. And it isn't just the overarching main story line, either. Few would argue that point: It's compelling, surprising, even chill-inducing, packing enough emotional punches to leave you stunned on occasion but always eager for more, which is what makes doing missions in TSW so much more enjoyable than many other MMOs.
One thing that The Secret World does extremely well is story.